Environment-friendly approach to hospital waste management practices is imperative, if health of staff, patients and quality of the environment would be guaranteed. To achieve this, information on quantity and composition of hospital solid waste generation is essential. The study explored cleaners’ perception of quantity and composition of solid waste produced in the activity areas of University College Hospital (UCH), Ibadan, Nigeria. Data were obtained through perceptual rating of cleaners that dealt directly with solid waste in UCH. Cleaners were required to rate the level of generation of fourteen identified solid waste components peculiar to hospitals as found in literature. Data for the study were collected through the use of structured questionnaires, using purposive sampling technique. One of every cleaner in each of forty (40) selected units in the study area was surveyed randomly. Cleaners were asked to rate solid waste components generated in each unit using a five Likert scale. Findings of the study showed that the mean WGI for the study area was 2.3. Seventeen activity areas had their mean WGI higher than the mean index (), while the remaining thirteen had negative deviations around the index. It was established that level of perception of medical solid waste generation in the areas other than clinics and wards was very low. It was found that 95% of the activity areas sampled were perceived to produce high quantity of nylon/polythene/plastics waste. Mean results shows variation in the quantity and components of solid waste generated in the activity areas of UCH. Therefore, the input of cleaners in assessing solid waste quantity and characteristics in hospitals is very important for effective waste management strategy.