A functional peritoneal dialysis catheter is essential for continuous ambulatory peritoneal dialysis to be an effective form of dialysis. The most common mechanical problems that hinder adequate function include obstruction, leaks, hernias, hemoperitoneum, and pain. The reported incidence of mechanical problems varies from 12% to 73%. Symptoms, diagnostic tests, risk factors, and treatment strategies are reviewed. Surgical intervention and catheter replacement are often required to resolve mechanical problems. Avoidance of mechanical problems reduces the risk of interruptions in peritoneal dialysis therapy.