This study analysed clinical features and laboratory investigations in 145 patients with tuberculous peritonitis diagnosed by peritoneoscopy at this hospital between 1984 and 1988. Tuberculous peritonitis was found in 2% of all patients with tuberculosis and in 59.8% of all those with abdominal tuberculosis admitted to the hospital during the study period. Tuberculous peritonitis was more common in women than men (1.4:1) and was most frequently encountered in the third and fourth decades of life. The commonest presenting symptoms were abdominal swelling (73.1%), fever and night sweats (53.8%), anorexia (46.9%), weight loss (44.1%), and abdominal pain (35.9%). The mean duration of symptoms was 1.5 months. Ascites was the commonest (95.2%) physical sign. Tuberculin skin testing was positive in 57.6% of patients (n = 118). The mean erythrocyte sedimentation rate was 75 mm/1st hour (n = 58). Chest radiography on 98 patients showed pleuropulmonary pathology in 40 patients (40.8%). Sputum examination confirmed active pulmonary tuberculosis in 26 patients. The ascitic fluid was an exudate in 96.4% and a transudate in 3.6% of patients, with 91.3% showing a straw coloured ascites. Cirrhosis, detected by biopsy specimen, was a finding in 6.2% of patients.