Development of diseases in cultivated crops depends on the complex interrelationship among host, pathogen and prevailing environmental conditions. In nature, plants are rarely, if ever, subject to the influence of only one potential pathogen and this is especially true of soil-borne pathogens like fusarium wilt (Fusarium oxysporum). In the present study, the co-occurrence of root-knot nematode (Meloidogyne species) and Fusarium oxysporum f.sp. lycopersici was surveyed in the main tomato growing areas of the central rift valley of Ethiopia.