Wiawso Diocese is tantamount to the Western North Region of Ghana which is typically a rain forest region. It has a total land area of 8,696 square kilometres.
The diocese is bounded by eight dioceses. It is bounded by Sunyani diocese to the north; Goaso to the north-east; Kumasi Archdiocese to the east; Obuasi diocese to the south-east; Cape Coast diocese to the south; Sekondi-Takoradi diocese to the south; then the diocese of Grand Bassam and Abenguro both in the Republic of the La Cote D’Ivore to the west.