Background <p>Alcohol consumption is linked to varied health outcomes. While alcohol appears to have a protective effect on renal function, the impact on patients with diabetes mellitus (DM) and hypertension (HTN) remains unclear. This cross-sectional observational study aims to explore the association between alcohol use and renal function, particularly for individuals with these comorbidities.</p> Methods <p>Data from participants in the Taiwan Biobank were analyzed. Participants were divided into drinkers and non-drinkers. Drinkers were defined as an alcohol intake of 150 mL or more per week for at least six months. Renal function was assessed using creatinine levels and 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine for estimated glomerular filtration rate (eGFR). Multivariate multiple regression models were used to examine the relationships between alcohol consumption, DM, HTN, and renal function.</p> Results <p>Drinkers had better renal function than non-drinkers, with higher eGFR values and lower creatinine levels. Alcohol consumption was linked to better renal function in DM patients but not HTN patients. A three-way interaction (drinking/DM/HTN) also revealed improved renal function.</p> Conclusions <p>This study suggests that alcohol consumption may be associated with better renal function outcomes, particularly in patients with DM and HTN. However, these findings should be interpreted cautiously given the cross-sectional nature of the study. Further longitudinal and mechanistic research is warranted to validate the findings.</p> Clinical trial number <p>Not applicable.</p>