Maung Maung served in a legal capacity in General Ne Win's caretaker government from 1958 to 1960. Following Ne Win's 1962 military coup, Maung Maung became Chief Justice and, although a civilian, was a prominent member of the central committee of the BSPP. He played a large part in shaping the 1974 constitution and subsequent changes to the judicial system. On 19 August 1988, amidst a series of large-scale demonstrations, the People's Assembly declared Maung Maung President and BSPP Chairman. Anti-government demonstrations continued and widespread disruptions resulted in another military coup led by Saw Maung on 18 September 1988. After his brief spell in power in 1988, Maung Maung disappeared from the public eye, although it was rumoured that he helped draft the election law governing the 1990 general election. He also served in various capacities in the successive governments of Myanmar as Attorney-General, Supreme Judge-General and other positions.