A 45-year-old woman who was treated with continuous ambulatory peritoneal dialysis (CAPD) developed recurrent peritonitis characterized by cloudy effluents, elevated white blood cell (WBC) counts (predominantly lymphocytes), and negative culture results. This case report suggests that she may have had viral peritonitis as indicated by a positive viral culture, the presence of viral antibodies in serum and peritoneal dialysis effluent (PDE), hematological findings, and cell surface receptor studies. The possibility of a viral cause should be considered in patients with culture-negative peritonitis, especially if they do not respond to antibiotics.