The predominant nematode species found on plantain in southern Nigeria was Helicotylenchus multicinctus which occurred at all 68 sites sampled. Hoplolaimus pararobustus. Pratylenchus coffeae and Radopholus similis were found at 64, 50 and 46% of the sites, respectively, while Meloidogyne spp. second stage juveniles were found at 68% of the sites. Other nematode species occurred at less than 5% of the sites and included Helicotylenchus dihystera. P. zeae, P. brachyurus, Rotlylenchulus reniformis, Scutellonema and Criconemoides spp, H. multicinctus and P. coffeae occurred at high densities (on average about 10 500 and 3500 nematodes/100 g fresh root weight. respectively), compared to the other species. P. coffeae was more common in the west and mid-west of southern Nigeria, while R. similis was more common in the cast. Factors, derived from a principal component analysis of observations of damage caused by nematodes, the banana weevil Cosmopolites sordidus and the fungus Mycosphaerella fijiensis, the cause of Black Sigatoka, were related to plant growth observations. The results suggest that P. coffeae followed by R. similis are the major biotic constraints of plantain production in southern Nigeria. Higher losses are anticipated by these plant parasitic nematodes than by either M. fijienis or C. sordidus.