Nematode pathogenicity experiments on Musa host plants were carried out in pot trials. Both the final nematode population densities and percentages root necrosis on different host plants were higher for the Radopholus similis population from Mbarara than for the populations from Namulonge, Ikulwe and Mukono (Uganda). The R. similis population from Mbarara managed to break the resistance of the diploid banana Pisang Jari Buaya, a known worldwide source of resistance to R. similis. The diploid banana hybrid TMB2× 9128-3 and the triploid dessert banana Yangambi km5 showed resistance against the four R. similis populations. These results indicate that differences in pathogenicity among different R. similis populations exist and should be taken into consideration for plantain and banana germplasm enhancement.