A review of patients with bacterial peritonitis and ascites revealed six patients with gastrointestinal tract perforation into their ascitic fluid and 33 episodes of spontaneous bacterial peritonitis in 32 patients. Signs and symptoms were not helpful in differentiating the two groups; however, ascitic fluid analysis was found to be useful. All patients with perforation peritonitis fulfilled at least two of the following criteria: ascitic fluid total protein ± 1 gm per dl, glucose < 50 mg per dl and lactate dehydrogenase ± 225 mU per ml. In only two episodes of spontaneous bacterial peritonitis were two of the criteria fulfilled.