In Fusarium section Liseola, the teleomorph is used to identify mating populations that represent different biological species when distinguishing morphological characters are absent in the anamorph. The Gibberella fujikuroi mating populations to which strains of Fusarium section Liseola belong were determined for isolates from sorghum grown at Ifakara, Ilonga and Kachiri, Tanzania. Representatives of all of the mating populations (A–F) were recovered at Ilonga, but C and E were absent at Ifakara and C was absent from Kachiri. The frequency of the different mating populations was similar at all three sites with A (21%) and F (49%) being the most frequent and C and E the least frequent, if they were recovered at all. The relative proportions of mating populations A and F in the population were significantly different from each other at Ilonga, but were not significantly different at Ifakara or Kachiri. Female fertile strains were more common within mating population A than within mating population F. The inbreeding effective population sizes for the A and F mating populations, respectively, were 69 and 91% of count based on mating type, and 88 and 53% of count based on male/hermaphrodite ratios.