SummaryDuring an 8-month crossover trial, 20 patients with chronic heart failure were treated foil-monthly periods with either bumetanide plus potassium supplement given simultaneously as a combined tablet, or bumetanide given separately and the potassium supplement then given later in the day. Patients received each regimen twice. Both treatments provided 1 mg bumetanide and approximately 16 mmol potassium daily. Potassium status of patients was followed clinically and by determinations of plasma potassium and blood cell potassium. The combined tablet appeared to avoid potassium depletion as effectively as the regimen using separate tablets. Since the combined tablet also ensures that the potassium supplement is actually taken and reduces the number of tablets a patient has to remember to take, it is concluded that it is to be preferred in patients with chronic heart failure.