The beneficial effects of application of spores of the mycorrhizal fungus Glomus sp. and the nematode parasitic bacterium Pasteuria penetrans to Meloidogyne incognita-infested soil on tomato growth and nematode reproduction were assessed in pot and microplot experiments. Tomato shoot and fruit weights in M. incognita-infected plants receiving a combined application of Glomus sp. and P. penetrans were greater than in untreated nematode-infected plants. In addition, the use of the mycorrhizal fungus and the nematode parasitic bacterium together conferred greater beneficial effects than their use alone. Final densities of M. incognita juveniles in soil were lower than the control by 40% and 18% in mycorrhizal plants (cvs. Kyoryoku-beiju and Pritz, respectively), by 38% and 53% in P. penetrans application, and by 61% and 57%, when both treatments were applied together. M. incognita did not affect root colonization by Glomus sp. when mycorrhizal inoculum was added two or three weeks before nematode inoculum. No significant effects of the mycorrhizal treatment on P. penetrans attachment to M. incognita or number of females infected by P. penetrans were observed.