After his retirement from playing football, he began his coaching career as manager of Iran national under-20 football team in 1968. He was selected as assistant coach of the national football team in 1970 and was again selected as this position in 1971 by Parviz Dehdari. After Dehdari's resignation in 1972, Ranjbar was appointed as caretaker manager of the national team which he led to the final victory in 1972 AFC Asian Cup. After team's success with Ranjbar, Iran Football Federation appointed Ranjbar as team's head coach and signed a two years contract with him but he was resigned after two months. He was out of football from 1972 to 1985. In 1985, he was appointed as technical manager of Esteghlal. Ranjbar was team manager of the national team in from 1998 to 2002.