ABSTRACTMicrocycle conidiation and nuclear events during conidiogenesis inCercospora kikuchiiare described. During conidiogenesis a single nucleus migrates into the conidial initial and subsequently gives rise to all nuclei in the conidium. Mature conidia include 13–27 cells, most of which are uninucleate. Many conidia were found to form conidiophores which bore secondary conidia (microcycle conidiation). In such conidia either apical or basal cells, or both kinds of cells formed conidiophores. These events inC. kikuchiiare compared to similar events in other fungi and their implications are discussed.