Background <p>While the relationship between genital hygiene practices and infection risk has been well-documented in various clinical settings, limited attention has been paid to preventive strategies specifically targeting male heart failure patients on dapagliflozin. This study aims to evaluate the impact of post-urination external genital cleaning on dapagliflozin medication adherence in male heart failure patients.</p> Methods and results <p>A multicenter, randomized, single-blind, parallel-controlled study was conducted with 1337 male heart failure patients on dapagliflozin therapy. The test group performed simple external genital cleaning post-urination, while the control group maintained routine care. Primary outcomes included genital fungal infection incidence, medication-related concerns, belief intensity, and medication adherence, assessed over a 1-year period. The test group demonstrated significantly lower rates of genital fungal infections compared to controls (0.75% vs. 3.14%, <i>P</i> = 0.002). Additionally, the test group showed higher dapagliflozin adherence rates (72.75% vs. 63.23%, <i>P</i> &lt; 0.001).</p> Conclusion <p>Post-urination external genital cleaning significantly improves dapagliflozin medication adherence in male heart failure patients.</p>