After the war, Lê Trọng Tấn continued to hold the position of Deputy Chief of the General Staff and Director of the Advanced Military Academy ("Học viện Quân sự cấp cao"). At the beginning of the Cambodian–Vietnamese War, Lê Trọng Tấn was commander of Vietnamese armed forces in the southern border of Vietnam from December 1978 to February 1979. From June 1978 to his death in 1986, Lê Trọng Tấn was Deputy Minister of Defence of Vietnam and Chief of the General Staff of the PAVN, succeeding general Văn Tiến Dũng. He died on 5 December 1986 at the age of 72.