Pathogenic Escherichia coli is found in the contaminated raw meat, raw milk, raw vegetables, contaminated water. The present work was based on the entomopathogenic effect of E.coli against stored grain pest Tribolium castaneum. Microbial screening of pathogenic bacteria was done by using different media such as TSB media, MacConkey media and Novobiocin media. Rearing of Tribolium castaneum was done and different stages of Tribolium castaneum such as larvae, pupae and adult were observed. Bioassay technique was applied for the detection of effect of E.coli against the Tribolium castaneum. The Bioassay was applied in two groups e.g. Control group and Experimental group. The pellet of grown culture of E.coli sample was mixed in the diet of Tribolium castaneum. The effect of E.coli was observed against 2nd Instar larvae of Tribolium castaneum upto three days and seven days.The mortality rate in both control group and Experimental group was approximately ? 10%. The results had shown that E.coli did not have any effect against Tribolium castaneum.