Genetic variability within four races of Fusarium oxysporum f. sp. pisi was assessed by random amplified polymorphic DNA (RAPD). Banding patterns generated from isolates of race 2 by 14 selected primers were uniform relative to patterns generated from races 1, 5, and 6. Isolates of races 1, 5, and 6 showed much greater variability within each race than did isolates of race 2. The high level of genetic variability among and within races of F. o. pisi allowed for fingerprinting of most of the isolates by examining patterns produced by several primers. Generalized race-specific patterns were not found for races 1, 5, and 6. The results suggested that races 1, 5, and 6 be grouped separately from race 2. Similarities and differences in banding patterns obtained by RAPD could be a useful molecular tool in evolutionary studies of the origins of different races.