Human atrial natriuretic peptide (ANP) is beneficial for the prophylaxis of acute renal failure (ARF) after liver transplantation (OLT). We evaluated renal function in OLT patients with or without ARF, describing cases unresponsive to loop diuretics successfully treated with continuous low-dose ANP infusion without hemodialysis. Twenty-seven consecutive adult-to-adult living donor liver transplantations (LDLTs) were performed in 26 patients. One case was excluded due to the need for continuous hemodialysis (HD) during the operation. Of the 26 cases, 6 (23%, group 2) developed ARF in the first 30 days after LDLT; the other 20 were ARF-free (group 1). The median follow-up was 24 months. No patient required either continuous or intermittent HD. Only one patient died due to multiple liver abscesses. Mean preoperative serum creatinine (sCr) value and intraoperative blood loss in group 2 were significantly higher than those in group 1. Three cases in group 2 failed to improve on high-dose loop diuretics with low-dose dopamine, exhibiting fluid overload. The remaining three cases in group 2 responded to conventional diuretic treatments. Continuous low-dose ANP was started 2, 4, or 5 days after LDLT, and urine output significantly increased after ANP administration. The serum creatinine values were 1.1, 1.2, and 1.1 at 1 month and 1.0, 0.9, and 0.6 mg/dL at 6 months after LDLT. Massive blood loss during the operation caused ARF, but did not affect renal function after LDLT. Continuous low-dose ANP improved renal function and diuresis for oliguric ARF patients, preventing the need for HD or continuous venovenous hemodialysis.