This study examined the effectiveness of the Public Procurement and Disposal of Public Assets Authority (PPDA) in promoting transparency in procurement processes at Kampala Capital City Authority (KCCA). Public procurement in Uganda consumes a substantial share of the national budget, and the transparency of procurement is central to value for money and public trust. The study was guided by three objectives: to assess the extent to which PPDA regulatory mechanisms enhance procurement transparency at KCCA; to examine the role of compliance and audit functions in curbing procurement malpractice; and to establish the relationship between PPDA oversight and transparency outcomes. A cross-sectional descriptive and correlational design was adopted, combining quantitative and qualitative approaches. Data were collected from a sample of 132 respondents drawn from procurement officers, user departments, contracts committee members, and providers using structured questionnaires and key-informant interviews. Descriptive statistics, Pearson correlations, and multiple regression were used to analyse the data. Findings revealed a positive and significant relationship between PPDA oversight and procurement transparency (r = 0.68, p < 0.01), with regulatory mechanisms (β = 0.41) and compliance/audit functions (β = 0.33) jointly explaining 54% of the variation in transparency outcomes. The study concluded that PPDA has been moderately effective, with capacity, enforcement delays, and political interference constraining full effectiveness. It recommended strengthening real-time monitoring, e-procurement adoption, and sanctions enforcement.