Background/aims: Tuberculous peritonitis is prevalent in developing countries and its diagnosis is still challenging due to the lack of specific clinical characteristics and the difficulty in obtaining tissue from the peritoneum without laparoscopy. Endoscopic ultrasound - guided fine needle aspiration is emerging as the most effective and safe method for obtaining tissue from the structures surrounding the gut lumen. Our study aimed to elucidate the efficacy of endoscopic ultrasound-fine needle aspiration of the peritoneum in the diagnosis of tuberculous peritonitis. Materials and Methods: Three patients (2 male and 1 female; aged 38, 25, and 65 years, respectively) suspected of having tuberculous peritonitis were recruited into the study. Clinical evaluation including computed tomography imaging and analysis of ascitic fluid were performed. Endoscopic ultrasound-fine needle aspiration biopsy of the peritoneum was performed trans-gastrically with a 19-gauge Pro Core needle in all patients. At least two different areas of the peritoneum suspected to be involved were sampled and paraffin-embedded cell blocks were prepared for each biopsy specimen. Results: Biopsy specimens were positive for Mycobacterium tuberculosis by polimerase chain reaction in 2 patients and positive for multinucleated giant cells in all patients. Treatment for tuberculosis resulted in the resolution of symptoms and ascites. No procedure-related complications occured. Conclusions: Endoscopic ultrasound-fine needle aspiration is an efficacious and safe method to obtain tissue from the peritoneum to use in the diagnosis of tuberculous peritonitis.