The Ga West Municipal Assembly was carved out of the erstwhile Ga municipal which was created in 1988 in pursuance of the government decentralization and local government reform policy. In 2004, the Ga Municipality was divided into two with Amasaman capital remaining the capital for the newly created Ga West Municipal. The Municipality was established by Legislative Instrument (L.I) 1858.The Municipality forms part of sixteen (16) Metropolis, Municipalities and Districts in the Greater Accra Region. the Municipality lies within latitude 5°35° North, 5°29’ North and longitude 0°10’ West and 0°24’ West. It shares common boundaries with Ga East and Accra Metropolitan Assembly to the East, Akwapem South to the North and Ga South and Ga Central to the South. It occupies a land area of approximately 284.08 sq km with about 412 communities.
The population of the Municipality according to 2010 population and housing census stands at 219,788 with 107,742 males and 112,046 females.