Genomic diversity among 14 isolates of Blastocystis hominis from 4 different geographic locations was examined by small-subunit rRNA (ssu rRNA) restriction-fragment-length polymorphisms (RFLP) using 5 different restriction endonucleases. On the basis of the observed RFLP patterns among the isolates, a total of 12 genotypes were identified, with 7 isolates exhibiting mixed RFLP genotypes. There was no correlation between B. hominis geographic origin and RFLP banding pattern or genotype.