Opuntia ficus-indica (OFI), also known as prickly pear has been used in traditional folk medicine. This is due to its medicinal properties that contribute to treatment of conditions including asthma, stomach ulceration, and diabetes. We carried out a cross-sectional study in 2018 in Kasese district, western Uganda to determine the traditional uses of O. ficus-indica and the anti-bacterial activity of the stem and fruit extracts of the plant. We interviewed participants using questionnaires and obtained data for the traditional uses. We also used the Agar well diffusion method to measure the antibacterial activity of the fruit and stem extracts of OFI. Data was analysed using SPSS version226.0 and a P value less than 0.05 was considered statistically significant after performing the one-way ANOVA test. Out of the 56 respondents, results showed that all (100%) of the respondents used prickly pear as food, 90% as ornamental, 80% as anti-ulcer, 60% as anti-constipation herb and 20% use the plant to cleanse the body. On the other hand, both fruit and stem extracts exhibited anti-bacterial activity as determined by the diameters of zones of inhibition: 27mm and 21mm respectively, compared to ampicillin (28mm) which was our positive control. The fruit extracts showed a higher anti-bacterial activity against E. coli bacteria than the stem extract (p<0.05) hence the rejection of the null hypothesis which stated that there is no significant variation in the anti-bacterial activity of Opuntia ficus-indica extracts from the stem and fruit.