In Vitro studies conducted during 1988, on the influence of malathion on phosphate solubilization by two bacterial and a fungal culture indicated differential response. Malathion inhibited organic acid production by Pseudomonas striata and Aspergillus awamori thereby decreasing phosphate solubilization significantly. Bacillus polymyxa, however, showed increased phosphate solubilization in the presence of malathion. Soil application of malathion showed a significant increase in dry matter content of greengram plants inoculated with P-solubilizers. Increased P-uptake by greengram plants due to inoculation with P-solubilizers and malathion application was observed