As observed in today's health care setting, ampules, which are designed for single-use are still persistently reused when there is a drug left-over, in order to aid the patients lessen the cost of health care. Leaving the ampules exposed, covered with a micropore or cotton plug in the patient's immediate bedside are believed to be beneficial in controlling contamination. This study aimed to compare the practices in safekeeping of opened single-use ampules in a closed plastic container in two environments utilizing a 2 x 3 experimental factorial research design. The specimens were collected from 180 ampules' neck after 6 hours of exposure, which were then cultured; the resultant colony forming units were counted expressed in CFU/mL. The use of various practices in safekeeping, use of a closed plastic container and two environments were not significant in preventing contamination. Results demonstrated that none of the current practices in safekeeping was effective in controlling the number of microbial contaminants. Hence adherence to their nature, "single-use" must be advocated despite circumstance of having a drug left over.