A collection of Mycosphaerella fijiensis, in total 71 isolates from 11 countries, of which 54 isolates were derived from the Ugandan Lake Victoria region, were analysed with regard to molecular markers and benomyl resistance to characterize the population structure. Forty-seven alleles from seven restriction fragment length polymorphism (PCR-RFLP) and five microsatellite markers were scored and utilized in the study. Using analysis of molecular variance (AMOVA), no significant genetic differentiation could be found between isolates from different leaves compared to isolates from a single leaf (P ¼ 0AE07). Exact tests of the allelic frequencies revealed no differences between isolates from different districts or between single-leaf-derived isolates compared to isolates derived from different leaves (P > 0AE05 in all cases except two, which, however, were shown to be of type-I error). Resistance to benomyl, analysed both by PCR and fungicide screening, revealed that all isolates were susceptible. Compiled information from the various datasets implied that the Ugandan M. fijiensis population in the Lake Victoria Basin constitutes a homogenous population, probably as the result of a recent founder event.