The election used the original 10 wards created by the Formation Electoral Arrangements in 1974. Each ward elected one councillor using first-past-the-post voting.[1]
Despite losing two seats, Labour maintained control of the district council, winning six of the 10 seats. The 1977 local elections were the first test for the nationalist Scottish Labour Party (SLP) which had been formed as a breakaway from Labour by South Ayrshire MP Jim Sillars alongside John Robertson and Alex Neil. The SLP achieved its best results in Cumnock and Doon Valley by winning two seats from Labour and taking more than 25% of the popular vote but the party ultimately fared poorly across the country. The Conservatives remained on one seat after losing their seat in Mauchline and gaining Catrine and Sorn. This was the last time the Conservatives would win a seat in the area until the 2017 local elections, 40 years later. The remaining seat was won by an independent candidate.