A greenhouse study was conducted to test the efficacy of G. mosseae and selected oils against R. solanacearum, either individually or in combination. This experiment was carried out in a greenhouse of the Plant Pathology Department, Faculty of Agriculture, Assiut University, Assiut, Egypt, during the 2010 season. The roots of the tomato seedlings (cultivar G.S.) were separately treated with each oil for 30 min at the time of transplanting, and G. mosseae was used at a rate of 10 g/kg soil with the top 10 cm of soil surface one week before planting. Pathogen inoculation was carried out as previously described in Section 2.2 when the seedlings reached the stage of three to four true leaves, and the disease index percentage was recorded four weeks after inoculation as previously described. The treatments were maintained with four replications, each replicate consisted of two seedlings, the pots were arranged in a completely randomized design, and the experiment was conducted twice.