The total population in the Diocese is estimated to be 907,116.

Religious denominations
The Catholic Diocese of Wiawso is located in an area where the population is composed of Christians, Muslims and Traditional adherents.  The total number of baptized Catholics is 106,385. Members of other Christian denominations are estimated to be 648,592.  Followers of non-Christian religions are also estimated to be 152,139. The total number of non-Catholics is 800,731.  All the religious denominations in the Diocese co-exist peacefully.