The cost of the Basilica of Our Lady of Peace, completed last year in Yamoussoukro, has been controversial in the West African nation, which is suffering its worst economic crisis in 30 years.
Heavy security was in place around Yamoussoukro, the native town of President Felix Houphouet-Boigny, to prevent anti-government demonstrations by recently legalized opposition parties.
Huge crowds gathered at the basilica in Yamoussoukro where the requiem mass began two hours late.