Petroleum and its refined products are major global resource used in industrial and transportation sectors for energy requirement throughout the world. The soil contamination ismost common problemfound in all over the world. The soil gets contaminated by petroleum product by various ways. Literatures suggest that the geotechnical properties of contaminated soil altered and result in detrimental effects. Here an attempt has beenmade to study the effect of Diesel contamination on geotechnical properties of black cotton soil. It was observed that various properties of black cotton soil are affected due to this contamination.