GMMB derives its powers from National Liberation Council Decree (NLCD) 387 of 1969, now known as Act 387 of 1969, which was further strengthened by the Executive Instrument (E.I.) 29 of 1973.

Ghana ratified the World Heritage Convention in 1975. Therefore, GMMB is guided by the operational guidelines for the implementation of the World Heritage Convention. GMMB is also guided by international guidelines, recommendations and charters.