This study evaluated the effect of infection by a mixture of nematode species (including Helicotylenchus multicinctus, H. dihystera, Hoplolaimus pararobustus, Meloidogyne spp. and Radopholus similis) on the root system size and shoot growth of six Musa genotypes. In addition, the influence of type of planting material on susceptibility and sensitivity to nematodes was assessed, comparing suckers (i.e., lateral shoots) and in vitro-derived planting material, produced through shoot-tip culture techniques. The Musa genotypes were the triploid (AAA-group) dessert banana cvs Yangambi km5 and Gros Michel, the triploid plantain cvs Agbagba and Obino l'Ewai (both AAB-group) and two IITA improved tetraploid plantain hybrids TMPx 548-9 and TMPx 5511-2. The study was carried out at the International Institute of Tropical Agriculture High Rainfall station at Onne in southeastern Nigeria in an ultisol soil. During vegetative growth, shoot growth of infected plants was less than that of non-infected plants. At flower emergence, a severe reduction in root system size (as much as 75%) was associated with moderate (in most cases less then 20%) reduction in corm and shoot growth characteristics. This indicates that Musa spp. plants grow relatively well with a reduced root system, i.e., the remaining root system can supply the plant with the necessary nutrients and water. Root systems of sucker-derived dessert bananas tolerated higher nematode population densities than those of in vitro-derived plants. Plantains were highly sensitive as moderate nematode population densities caused a severe reduction in root system size.