A stem grafting technique was used to determine the contribution of root and shoot tissues of bean (Phaseolus vulgaris L.) to the resistance response to the root-knot nematode, Meloidogyne incognita (Kofoid and White, 1919) Chitwood 1949. Stemgrafts were prepared between resistant (line A 211 or cultivar Nemasnap) and susceptible (Canario Divex) bean cultivars in all possible scion-rootstock combinations. Graft combinations in which the rootstock was resistant resulted in a resistant response to M. incognita, and those combinations in which the rootstock was susceptible resulted in a susceptible response, regardless of scion component. Resistance factors were therefore either localized within roots or not translocated basipetally through the stem graft union.