Public procurement transparency is the principal safeguard against the diversion of public resources, yet the effectiveness of regulatory oversight in securing it remains contested even where the legal framework is robust. This study examined the effectiveness of the Public Procurement and Disposal of Public Assets Authority in promoting procurement transparency at the Kampala Capital City Authority. Adopting a positivist philosophy and a crosssectional survey design, data were collected from 186 respondents drawn through stratified random sampling from a target population of 264 comprising KCCA procurement and disposal unit staff, contracts committee members, user department heads, accounting and internal audit personnel, evaluation committee members, and registered providers. A structured questionnaire measured four PPDA effectiveness dimensions, namely regulatory framework and guidance, procurement audit and compliance monitoring, electronic government procurement implementation, and enforcement and sanctions, against procurement transparency assessed through information disclosure, competitive access, process integrity, and accountability to stakeholders. Data were analysed using descriptive statistics, Pearson correlation, and multiple regression in SPSS version 26. Findings revealed that regulatory framework recorded the highest mean while enforcement and sanctions recorded the lowest. All four dimensions correlated significantly and positively with procurement transparency, with electronic government procurement implementation strongest (r = 0.693, p < 0.01), followed by procurement audit and compliance monitoring (r = 0.647, p < 0.01), enforcement and sanctions (r = 0.582, p < 0.01), and regulatory framework and guidance (r = 0.498, p < 0.01). The regression model was significant, F(4, 176) = 59.31, p < 0.001, explaining 57.4 per cent of variance. The findings address the MAPS Assessment finding that less than fifty per cent of key procurement information is published and that procurement data collection is weak (MAPS Initiative, 2023), and the observation that PPDA's regulatory role may conflict with its audit role (MAPS Initiative, 2023). The study concludes that digital systems rather than rule promulgation drive transparency and recommends full e-GP adoption, publication enforcement, and the separation of regulatory from audit functions.