Face-masking could reduce the risk of COVID-19 transmission. We assessed: knowledge, attitudes, perceptions, and practices towards COVID-19 and face-mask use among 644 high risk-individuals in Kampala, Uganda. In data analysis, descriptive, bivariate and multivariate logistic regression analyses, with a 95% confidence interval were considered. Adjusted-odds ratios were used to determine the magnitude of associations. P-values < 0.05 were considered statistically-significant. Majority: 99.7% and 87.3% of the participants respectively had heard and believed that face-masks were protective against COVID-19, while 67.9% reported having received information on face-mask use. Males, food market vendors, those with no formal education, and those aged 24-33, 44-53 and 54-63 years were 0.58, 0.47, 0.25, 1.9, 2.12, and 3.39 times less likely to have received information about face-mask use respectively. Majority, 67.8% owned locally-made, non-medical face-masks, while 77.0% of face-mask owners believed that they knew the right procedure of wearing them. Those who had received information on face-mask use were 2.85 and 1.83 times more likely to own face-masks and to perceive them as protective. Food market vendors were 3.92 times more likely to re-use their face-masks. Our findings suggest that Ugandan high-risk groups have good knowledge, optimistic attitudes and perceptions, and relatively appropriate practices towards COVID-19.