The article reports the case of an 11-year-old boy with tuberculous peritonitis. Tuberculosis (TB) can also affect the gastrointestinal tract, mesenteric lymph nodes and peritoneum. This involvement can occur as the only manifestation of tuberculous disease or in association with other localizations, such as the classic thoracic one. Diagnosis is not always easy, as the symptoms are not clinically specific and can be confused with other acute abdomen pictures. Evaluations in terms of radiological images do not give specific findings, and Mantoux and Quantiferon can be negative. Exploratory laparoscopy with biopsy tests and Mycobacterium research are often necessary for diagnosis. Therapy (anti-tuberculosis antibiotic therapy) is conservative, whenever possible, but sometimes it is necessary to combine surgical treatment and management can be difficult.