Except for a round-trip voyage to Okinawa early in September, the ship operated out of US Naval Base Subic Bay, Republic of the Philippines for the remainder of her deployment.

She headed for the Philippines on 25 May, arrived in Subic Bay on the 27th, and relieved USS Princeton as flagship of Amphibious Ready Group (ARG) Bravo VTG 76.5.

Her first operation, codenamed Beacon Torch, began on 18 June when US Marines of SLF Bravo were flown into the vicinity of Hoi An, located on the coast midway between the DMZ and the southern limit of I Corps tactical zone.

On 2 July, she received the special landing force back on board and immediately headed north to the coast of Quảng Trị Province to answer a call for assistance from Marine Corps units near Con Thien, which had suffered heavily from bombardments by the People's Army of Vietnam (PAVN).

The two battalion landing teams joined III MAF Marines based ashore in a week-long struggle, followed by an eight-battalion search and destroy sweep.

At dawn three days later, Tripoli's Marines stormed ashore in a combined waterborne-airborne amphibious assault on the exposed seaward flank of the Viet Cong (VC) 806th Battalion near Quảng Trị City.

Tripoli returned to the Vietnamese coast near Huế on the 20th and backloaded SLF Bravo in time for the Marines to participate in Operation Belt Drive.

In spite of swells 8–12 feet (2.4–3.7 m) high, a rain squall, 30- to 40-knot (46 mph; 74 km/h) winds, and visibility frequently less than 0.5 miles (0.80 km), the boat landings for Operation Fortress Sentry came off almost without a hitch.

Ashore near the Cua Viet River some 7 miles (11 km) south of the DMZ, the Marines moved inland, but encountered no enemy resistance until the 23d.

On the 17th, CH-53 Sea Stallion helicopters carried the battalion landing team to a point 10 miles (16 km) south of Phu Bai Combat Base in Thừa Thiên Province.

For Operation Swift Play, the Marines rode helicopters ashore to an area about 10 miles (16 km) southwest of An Hoa, deep inland in Quảng Nam Province.

The landing force remained ashore operating under the commanding general, 1st Marine Division, in defense of Danang through the months of August, September and November.

Three days later, Tripoli launched her fourth landing, another combined waterborne and airborne operation directed at an area in Quảng Nam Province, just south of Danang.

Tripoli continued support activities for the battalion landing team until 3 December when she offloaded what remained aboard of the Marines' equipment at Danang, in preparation for departing Vietnam for a liberty call in Hong Kong.

Both special landing forces "Alfa" and "Bravo," joined South Vietnamese troops and soldiers of the US Army's Americal Division in forming the cordon.

The expected enemy Tet 1969 offensive required South Vietnamese troops to be withdrawn from Operation Taylor Common, then in progress near An Hoa in Quang Nam Province.

She moved to Long Beach on the 23d to replace a cracked screw and departed that port on the 27th to return to the western Pacific reaching Subic Bay on 15 March.

During her return from Sasebo to Subic Bay, she received orders to deploy to the Indian Ocean with TF-74, a special contingency task force built around USS Enterprise in response to the Indo-Pakistani War, which erupted on 3 December.

On 29 June, Tripoli-assigned helicopters helped to transport 1,400 Vietnamese Marines from Tam My to the vicinity of Quang Tri City during the allied counteroffensive to recapture areas of the I Corps tactical zone, which had been overrun by PAVN during the Easter Offensive.

That necessity came shortly before noon on 11 July, when her helicopters helped to insert the reserve Vietnamese Marines battalion, picking them up near Route 553 and landing them behind enemy lines, about 1.5 miles (2.4 km) north-northwest of Quang Tri City.

The ship remained there and, when not plagued by material casualties to her main propulsion plant, conducted training preparatory to Operation End Sweep, the removal of American mines from North Vietnamese waters.

That morning, the commander of TF 78, Rear Admiral Brian McCauley, embarked on the Tripoli and began negotiations with North Vietnamese representatives over the conduct of Operation End Sweep.

The second deployment, from mid-February to late October 1976, saw a repetition of this routine, but also included a voyage to Guam for disaster relief duty as a result of Super Typhoon Pamela.

Tripoli proceeded into the northern Persian Gulf and assumed duties as flagship for airborne mine countermeasures operations there with HM-14 and Marine Light Attack Helicopter Squadron 773 (HMLA-773) deployed aboard.

Tripoli remained on station for seven days before finally setting course for Jubail to allow HM-14 to crossdeck to the USS New Orleans and then to Bahrain's Arab Shipbuilding and Repair Yard Company.

After months of training off Dubai, United Arab Emirates, USMCMG staff embarked on Tripoli on 20 January, and proceeded to the northern part of the Persian Gulf waters to perform their mission.

As damage control teams successfully overcame fires and flooding aboard Tripoli and Princeton, Impervious, Leader, and Avenger searched for additional mines in the area.

Charts and intelligence captured from Iraq showed the mine field where Tripoli and Princeton were hit was one of six laid in a 150 miles (240 km) arc from Faylaka Island to the Saudi-Kuwaiti border.

Assuming duties with other ships in the northern Persian Gulf, Tripoli prepared to conduct amphibious operations in response to any further southward movement by Iraqi forces.

In December 2006, the ship was towed to Pearl Harbor, Hawaii, where she had a high-tech role as a launch platform with the United States' developing ballistic missile defense program.