Results of a transmission and scanning electron microscopy study of the mitosporogenous process in Cercosporella ugandensis are given. The details hitherto deduced from light microscopy concerning mitospore initiation, maturation and secession are confirmed. In addition, an ultrastructural basis, in terms of wall layer deposition, is provided for mitospore maturation, scar structure and development, and mitospore secession. This implies a quite separate mode of delimitation and liberation in comparison to other fungi in the Cercospora-like generic assemblage.