| February 1965 |
| 7 | VC attack US compound at Pleiku. |
| 7 | First 1965 US air strike against NVN hits Dong Hoi Barracks. |
| 8 | President Johnson orders evacuation of US government sponsored dependents from SVN. |
| 8 | President Johnson orders Hawk air defense missiles to SVN. |
| 9 | First elements of USMC 1st LAAM Bn operational at Da Nang. |
| 9 | Gen Khanh names Nguyen Xuan Oanh acting premier. |
| 10 | VC blow up US BEQ at Qui Nhon. |
| 15 | Dr. Phan Huy Quat named premier, replacing Oanh. |
| 16 | Largest VC weapons cache of war to date seized at Vung Ro Bay. |
| 19 | Jets used for first time in SVN as USAF B-57's attack VC in Binh Dinh sector. |
| 19 | Last US government sponsored dependents flown out of SVN. |
| 22 | Maj Gen Tran Van Minh replaces Khanh as CINCRVNAF. |
| 25 | 600 ROK troops arrive in SVN. |
| 27 | US White Paper accuses NVN of deliberate campaign of aggression. |
| March 1965 |
| 8 | First USMC unit (3d Bn, 9th Marines) lands at Da Nang. |
| 15 | Highway 19 from Qui Nhon to Pleiku reopened after almost two months without traffic. |
| 19 | 716th MP Bn arrives in SVN to provide security for US installations. |
| 21 | USMACV publicly confirms riot-control agents have been used in SVN. |
| 22 | US aircraft hit first NVN radar site. |
| 27 | About 30 Claymore type mines accidentally detonated at Plei-Do-Lim Special Forces Camp with heavy casualties. |
| 28 | 7th BLT undertakes SVN coastal surveillance. |
| 30 | US Embassy in Saigon damaged by VC explosives. |
| 30 | USAF aircraft strike Dong Hoi airfield, first NVN airfield hit. |
| April 1965 |
| 1 | U.S. 1st Log Comd is established. |
| 4 | First US planes are shot down by MIG's over NVN. |
| 5 | Pacification program renamed Rural Reconstruction under new GVN Central Rural Reconstruction Council. |
| 9 | USN jet shoots down MIG over South China Sea southwest of Hainan Island with Sidewinder missile; one USN jet downed by MIG in same dogfight. |
| 14 | VNAF planes fly first night attack mission over NVN. |
| 16 | First NVN SAM site reported under construction near Hanoi. |
| 19 | SECDEF, CINCPAC, CJCS, COMUSMACV at Honolulu conference. |
| May 1965 |
| 3 | Initial elements of 173d Abn Bde arrive in SVN. |
| 4 | US begins 2-day halt of ROLLING THUNDER aerial armed reconnaissance and strike missions over NVN while conducting intensive aerial photo reconnaissance missions. |
| 5 | POLNAR Advisory Directorate established within the USMACV staff. |
| 6 | SVN Armed Forces Council dissolves itself, votes confidence in Premier Quat. |
| 7 | US Marines and Seabees land and begin construction at Chu Lai. |
| 7 | III MAF activated under command of Maj Gen W. R. Collins, USMC. |
| 11 | VC attack provincial capital of Song Be. |
| 13 | US begins 5-day peace move and standdown of ROLLING THUNDER aerial armed reconnaissance and air strike missions over NVN. |
| 14 | 1st ANGLICO units deployed in SVN. |
| 14 | US Embassy announces creation of Joint US Public Affairs Office (JUSPAO). |
| 16 | Bien Hoa airbase rocked by series of accidental explosions. |
| 18 | US resumes NVN air raids. |
| 20 | USS Hamner fires Navy's first NGF mission in SVN. |
| June 1965 |
| 2 | Advance party of 1st Bn RAR arrives in SVN. |
| 4 | Brig Gen L. W. Walt assumes command of III MAF replacing Maj Gen W. R. Collins. |
| 9 | USA combat engineers begin construction of base at Cam Ranh Bay. |
| 10 | Battle of Dong Xoai begins with heavy casualties on both sides. |
| 11 | Premier Quat resigns. |
| 14 | Generals form National Leadership Committee under Maj Gen Nguyen Van Thieu. |
| 16 | Explosive charge damages TSN civilian passenger terminal. |
| 17 | First MIG's shot down by USN aircraft over NVN. |
| 18 | First B-52 bomber raid in SVN. |
| 19 | Air Vice Marshall Nguyen Cao Ky assumes premiership. |
| 25 | VC mines blast My Canh floating restaurant in Saigon. |
| 27 | 173d Abn brigade-sized operation in Zone D with ARVN and RAR is first major US ground combat offensive of war. |
| July 1965 |
| 1 | VC attack Da Nang and Soc Trang air bases. |
| 7 | 8,000 additional Marines land at Da Nang end Qui Nhon. |
| 8 | Gen Taylor resigns as Ambassador to SVN; Henry Cabot Lodge named as successor. |
| 8 | SFC Isaac Camacho escapes after 20 months as VC prisoner. |
| 12 | 2d Bde, 1st Inf Div, begins landing in SVN. |
| 15 | USMACV confirms presence of a NVA 101st Regiment in SVN. |
| 16 | B-52's used in support of ground operation for first time. |
| 16 | SECDEF and Ambassador-designate Lodge arrive in Saigon. |
| 20 | US Army Support Command, Vietnam redesignated US Army, Vietnam, with General Westmoreland as commander and Gen Norton as Deputy CG. |
| 20 | SECDEF departs for Washington. |
| 20 | First USCG vessels to see action in combat zone since WW II arrive in SVN. |
| 21 | New Zealand Field Artillery Btry arrives in SVN. |
| 24 | First US aircraft downed by SAM over NVN. |
| 27 | US aircraft hit SAM sites in NVN for first time. |
| 28 | President Johnson announces US troop strength in Vietnam will rise to 125,000. |
| 28 | USMC and ARVN forces begin LIEN KET 4, the first combined land operation in the war. |
| 29 | 1st Bde, 101st Abn. Div, lands at Cam Ranh Bay. |
| 30 | Ambassador Taylor leaves RVN at end of his tour of duty. |
| 30 | Rural Reconstruction renamed Rural Construction under new GVN Ministry of Rural Construction. |
| 30 | Operational control of USN coastal surveillance (MARKET TIME) shifted from COMSEVENTHFLT to COMUSMACV. |
| August 1965 |
| 1 | USA Task Force Alpha activated as the first USA field force HQ in SVN. |
| 1 | Battle at Du Co Special Forces Camp begins. |
| 2 | COMUSMACV and CINCPAC at Honolulu conference. |
| 7 | CG III MAF designated Senior Advisor, I Corps, and assumes opcon over I Corps Advisory Group. |
| 9 | VNAF receives first USAF B-57's. |
| 14 | 7th Marine Regt (Rein) begins landing at Da Nang and Chu Lai. |
| 18 | III MAF begins Operation STARLIGHT. |
| 20 | Ambassador Lodge arrives in Saigon to begin his second tour. |
| 24 | VC mortar attack hits Bien Hoa air base. |
| 31 | Military Payment Certificates introduced to replace US currency is SVN. |
| September 1965 |
| 7 | US and SVN Marines begin five-day Operation PIRANHA |
| 11 | Group of Montagnard tribesmen disarmed in Darlac Province in GVN move against FULRO. |
| 12 | First elements of the USA 1st Cav Div (AM) land at Qui Nhon. |
| 15 | Group of Montagnards reaffirms loyalty to .GVN at Ban Me Thuot ceremony. |
| 18 | 101st Abn, 1st Cav Div (AM), and ARVN units begin four-day Operation GIBRALTER. |
| 25 | Task Force Alpha redesignated Field Force Vietnam and assumes opcon over II Corps Advisory Group and all USA units in II CTZ. |
| 28 | CINCPAC and COMUSMACV at Honolulu conference. |
| 30 | VC suffer heavy losses in week-long battle at Phu Cu Pass. |
| November 1965 |
| 1 | 1st Cav Div (AM) in its first offensive combat mission, SILVER BAYONET, near Plei Me. |
| 1 | CG, 1st Inf Div, assumes opcon over all USA units and Free World attachments in III CTZ. |
| 2 | Air base at Cam Ranh Bay operational for tactical jet aircraft. |
| 2 | Lt Gen J. L. Throckmorton: DEPCOMUSMACV, leaves Vietnam. |
| 6 | Lt Gen J. A. Heintges, USA,.replaces Lt Gen Throckmorton as DEPCOMUSMACV. |
| 7 | USMACV publicly confirms presence of five NVA regiments in SVN. |
| 9 | 173d Abn Bde concludes five day Operation HUMP. |
| 10 | US and SVN Marines join in Operation BLUE MARLIN, first combined amphibious landing in RVN. |
| 14 | Battle of Ia Drang Valley begins. |
| 22 | VC mortar Soc Trang airfield. |
| 27 | VC overran ARVN 7th Regt at Michelin plantation. |
| 27 | VC release USA PW's Smith and McClure in Cambodia. |
| 28 | Defense Secretary McNamara arrives in Saigon for two day visit. |
| December 1965 |
| 1 | CG, 1st Inf Div, designated Senior Advisor, III Corps, and assumes opcon over III Corps Advisory Group. |
| 2 | USS Enterprise enters combat, sending sorties against VC targets in SVN. |
| 4 | VC terrorists bomb Métropole BEQ in Saigon. |
| 8 | US Marine and ARVN elements begin 11-day Operation HARVEST MOON. |
| 10 | CINCPAC and COMUSMACV at Honolulu conference. |
| 14 | USAF hits Uong Bi thermal power plant near Haiphong. |
| 18 | FULRO briefly seizes control of Quang Duc provincial headquarters at Gia Nghia. |
| 24 | US FWMAF and RVN forces begin 30-hour Christmas cease-fire. Bombing of NVN ceases. |
| 29 | 3d Bde, USA 25th Inf Div, begins arriving in SVN. |