A total of 20 random primers (10-mers) were used to amplify RAPD markers from the genomic DNA of four Trypanosoma brucei stocks from East and West Africa, four T. evansi stocks from Africa, Asia and South America and one T. equiperdum stock from Asia. Between 65 and 88 reproducible fragments ranging from 0.25 to 2.15 kb were generated from these stocks depending on the stock/primer combination. The imilarity coefficient (SC) among the stocks of T. brucei from Kenya, Nigeria, Tanzania and Zambia ranged from 62.9% to 74.0% (average: 67.6%). The SC among the stocks of T. evansi from Kenya, China and Brazil was 76.4%-95.5% (average: 86.4%), while the SC between T. evansi stock from China and Brazil was 95.5%. For T. evansi and T. equiperdum, the SC among the stocks ranged from 81.2% to 94.4% (average: 87.6%). As for the SC among the stocks of T. brucei and T. evansi, it was found to be from 54.7% to 80.3% (average: 68.0%) and the SC among stocks of T. brucei and T. equiperdum was from 59.4% to 76.9% (average: 68.1%). Our results indicate that the stocks of T. evansi from China and from Brazil are more closely related to the stock of T. equiperdum from China than to the stocks of T. evansi isolated from Kenya and to the stocks of T. brucei. In addition, our results further support the hypothesis that T. evansi stocks from China and Brazil could have arisen from a single lineage. The possible evolution of T. evansi and T. equiperdum is also discussed.