Aim:The bacterial agents can be isolated even from the aerosol, hands, cloths,and floors of the laboratory .So, the microbiological agents isolated from these areas can act as contaminant in the microbiology laboratory and may be an obstacle in the routine processing and culture of the specimen. This leads to the false positive results and false negative results. As a consequence of which, inaccurate therapeutic regimens are prescribed to the patients, this causes unusual serious effects in the other unaffected parts of the body.The purpose of this study was to illustrate the bacterial agents that are responsible to act as a contaminant in the laboratory. Methods:The samples were collected from the floors,working surface and aerosol of the laboratory whereas the samples were also obtained from the hands and cloths of the laboratory staffs of Chitwan Medical College and Teaching Hospital. The isolates were identified bythe standard microbiological protocols applied routinely in the lab. Results:Out of 180 samples, growth was observed in 38 of them. Among 38 positive samples, Micrococcusspp. was isolated in 14(36.8%) followed by Bacillus subtilis in 7 (18.4%). Diphtheroids were observed in 4 samples (10.5%). Staphylococcus epidermidis was found in 6 (15.8%) samples whereas Staphylococus aureus were isolated in 5(13.1%)samples. Conclusion:Hence, the bacteriological agents can be isolated from various areas of laboratory and may act as a contaminant which might degrade the quality or the accuracy of the reporting of the results.