Diesel soil contamination is considered a serious environmental problem with widespread negative effects on the environment, human health, and living organisms. The aim of this study is to investigate the efficiency of some local bacterial species to degrade diesel. Bacterial species were isolated from soils contaminated with hydrocarbons from areas south of Babylon Governorate . To estimate the efficiency of biodegradation of diesel, gravimetric analysis was used. The results showed that: Enterobacter cloacae complex degraded 44.44% (1%, 10 day) and 57.14% (1%, 15 day); 50% at 3% for both periods. Escherichia hermannii: 11.11% (1%, 10 day), 14.28% (1%, 15 day); 13–20% at 3%. Citrobacter sadlakii: 28.57% (1%, 10 day), 66.70% (1%, 15 day); 30–62.50% at 3%. Staphylococcus lentus: 66.70% (1%, 10) day, 71.42% (1%, 15 day); 30–37.50% at 3%. Aeromonas salmonicida: 33.33% (1%, 10 day), 42.85% (1%, 15 day); 40–50% at 3%. Sphingomonas paucimobilis: 22.22% (1%, 10 day), 28.57% (1%, 15 day); 20–25% at 3%. All six bacterial species possessed the alk gene (confirmed by PCR), responsible for petroleum hydrocarbon degradation. These strains show strong potential for bioremediation of diesel-polluted sites.