OBJECTIVE:: HIV prevention service delivery models that offer product choices, and the option to change preferences over time, may increase prevention coverage. Outpatient departments in sub-Saharan Africa diagnose a high proportion of new HIV infections, but are an understudied entry point to biomedical prevention. DESIGN:: Individually randomized trial of dynamic choice HIV prevention (DCP) intervention vs. standard-of-care (SOC) among individuals with current/anticipated HIV exposure risk at outpatient departments in rural Kenya and Uganda (SEARCH; NCT04810650). METHODS:: Our DCP intervention included 1) product choice (oral pre-exposure prophylaxis [PrEP] or post-exposure prophylaxis [PEP]) with option to switch over time, 2) HIV provider- or self-testing, 3) service location choice (community vs. clinic-based), 4) provider training on patient-centered care. Primary outcome was proportion of follow-up covered by PrEP/PEP over 48 weeks assessed via self-report. RESULTS:: We enrolled 403 participants (61% women; median 27 years, IQR 22,37). In the DCP arm, 86% ever chose PrEP, 15% ever chose PEP over 48 weeks; selection of HIV self-testing increased from 26% to 51% and of out-of-facility visits from 8% to 52%. Among 376/403 (93%) with outcomes ascertained, time covered by PrEP/PEP was higher in DCP (47.5%) vs. SOC (18.3%); difference=29.2% (95%CI:22.7–35.7%; p < 0.001). Effects were similar among women and men (28.2% and 31.0% higher coverage in DCP, respectively) and larger during periods of self-reported HIV risk (DCP 64.9% vs. SOC 26.3%; difference=38.6%; 95%CI:31.0–46.2%; p < 0.001). CONCLUSION:: A dynamic choice HIV prevention intervention resulted in two-fold greater time covered by biomedical prevention products compared to standard-of-care in general outpatient departments in eastern Africa.