The interaction between the Vesicular-Arbuscular (V-A) mycorrhizal fungi and the root pathogen Sclerotium rolfsii Sacc. was studied in a pot culture experiment. Simultaneous addi­tion of V-A mycorrhizae and the pathogen reduced the severity of disease. Among the mycorrhizae tested, Glomus fasciculatum (Thaxt.) Gerd. and Trappe, was more effective in checking the disease incidence. The shoot P content, root colonization by mycorrhizal fungi and extra matrical chlamydospore count was highest in plants inoculated with only Glomus fasciculatum and lowest in plants inoculated with only the pathogen.