The random amplification of polymorphic DNA (RAPD) technique has the potential to produce large amounts of characterisation data very quickly and simply, using far less DNA than conventional restriction-fragment-length polymorphism (RFLP) analysis. In the present study we assessed genetic heterogeneity among 34 Trypanosoma brucei gambiense isolates from various endemic areas in Africa by the RAPD technique using 8 arbitrary primers and compared the results with those obtained previously from RFLP analysis of polymorphisms in 5 variant surface glycoprotein (VSG) genes. The isolates were compared both among themselves and with 3 T. b. non-gambiense isolates. Most of the primers produced RAPD profiles specific for T. b. gambiense, with 4 primers showing marked polymorphisms between T. b. gambiense and non-gambiense stocks. These primers also showed minor variations between the T. b. gambiense stocks, and 2 revealed differences between Cameroonian stocks. These results were comparable with those produced by RFLP analysis, where certain polymorphisms are characteristic of T. b. gambiense. Numerical analysis showed a high correlation between the RAPD and RFLP data, with genetic variation being detected at a finer level by RAPD analysis. We conclude that RAPD analysis provides a simple and accurate method for the characterisation of T. b. gambiense.