Purpose: To determine the type and incidence of predominant microorganisms in certain non-sterile pharmaceuticals immediately after collection and one year later. Methods: All pharmaceutical samples were subjected to the following examinations: total bacterial count and presence of microbial pathogens, using conventional techniques. Attempts were also made to identify the isolates. The bioburden rate of some of the syrups and oral drops after storage for 0, 6 and 12 months were evaluated in order to assess the effect of storage on microbial contamination level. Results: Microbial load varied among the pharmaceutical preparations with the highest microbial load in suspensions and the lowest in tablets. Bacterial counts ranged from 10 to more than 103 CFU per ml or g. The bacterial count at 6 and 12 months were significantly different from that at 0 month (p < 0.05). The isolated organisms were either of human flora types, essentially Gram-positive bacteria, or airborne fungi. Conclusion: The isolated organisms were either of human flora types, principally, Gram-positive bacteria, or air-borne fungi and the stored preparations lack an effective preservation. Several measures, including equipment automation, monitoring programs and post-marketing surveillanceare required to reduce the level of microbial contamination of non-sterile pharmaceutical products. � Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City.