Peritoneal tuberculosis is rarely observed in European countries. We report on peritoneal tuberculosis in two female immigrants from Somalia and Columbia who presented with diffuse abdominal pain, fever, weight loss and exudative, lymphocytic ascites. Laboratory investigations showed an increase in C-reactive protein and carcinoma antigen 125 serum levels. Nodular peritoneal lesions and adhesions were detected by ultrasound and computed tomography. In both patients, peritoneal biopsy from laparoscopy revealed epitheloid granulomas with central necrosis and multinucleate giant cells. Microscopy and PCR analysis were, however, negative for Mycobacterium tuberculosis in both patients. Despite repeated testing, ascites culture became positive for M. tuberculosis in only one patient. Shortly after starting antituberculous drug treatment, both patients improved, ascitic fluid disappeared and C-reactive protein and carcinoma antigen 125 serum levels returned to normal. Even in Western countries, peritoneal tuberculosis should be considered in any febrile patient with abdominal signs and symptoms, particularly if ascites is present. Empirical antituberculous treatment is justified in patients with clinical and histological features highly suggestive of peritoneal tuberculosis, even in cases with negative results from microscopy, culture and PCR analysis.