The nosocomial infections are acquired unknowingly by patients admitted in hospitals during the course of treatment and it is all due to the microbial biopollutions of the hospital environment in the form of susceptible and resistant microorganisms. These opportunistic infections are caused by microorganisms that normally do not cause serious diseases in healthy people and may occur in individuals whose immune systems are impaired or compromised in some or other way. Several harmful bacteria and fungi have been reported. The most common harmful bacteria isolated from the hospital environment of People's Medical College, Bhopal are Staphylococcus, Streptococcus, Pseudomonas, Escherichia Klebsiella, Clostridium and Pneumococcus. And, the fungi being reported are Aspergillus, Penicillium, Mucor, Rhizopus, Fusarium, Neurospora and the yeast Candida. The present work deals with the study of those microorganisms that cause medical biopollutions with special reference to nosocomial infections in human.