What is known and objective: Angiotensin receptor blockers (ARBs) are medications commonly used for treating conditions such as hypertension. However, ARBs are frequently associated with hyperkalemia, a potentially critical adverse event, in high-risk patients. Although both the liver and the kidney are major elimination routes of ARBs, the relationship between hepatorenal function and ARB-related hyperkalemia has not yet been investigated. The purpose of this study was to evaluate the risk of hyperkalemia, in terms of various hepatorenal functions, for hospitalized patients newly initiated on ARB treatment. Methods: We evaluated ARB-related hyperkalemia in a cohort of 5530 hospitalized patients, who had not previously used ARBs, between April 12, 2004 and May 31, 2012. Hepatorenal function was assessed by the Model for End- Stage Liver Disease (MELD) score. Hyperkalemia risk was assessed by hepatorenal function, risks were categorized into the four MELD scoring groups, and the groups were compared with one another. Results and discussion: The MELD score was significantly different between the hyperkalemic and non-hyperkalemic groups (independent t-test, p<0.001). The MELD score 10-14, 15-19, and ≥20 groups showed higher risks of hyperkalemia than the lowest MELD score group (log-rank test, p<0.001; multiple Cox proportional hazard model, HR 1.478 (p=0.003), 2.285 (p<0.001), and 3.024 (p<0.001), respectively). What is new and conclusion: The MELD score showed a stronger predictive performance for hyperkalemia than either serum creatinine or estimated glomerular filtration rate alone. Furthermore, the MELD score showed good predictive performance for ARB-related hyperkalemia among hospitalized patients. The clinical implications and reasons for these findings merit future investigation.