RESUMEN
More than 80 percent of new cases of TB are pulmonary TB produced by three different causes as follows: Adjacency to mucosal surfaces, anatomical adjacency of organs and lymphohematogen. Incidence of TB in different organs is different and in most of the cases is related to lymph node. In this article two cases of extrapulmonary TB is presented along with emphasizing diagnostic process. The first case was a 14- year- old girl with fever and abdominal pain for one month whom was treated for typhoid at first but complications such as arthritis and ascites happened. Ascites fluid for M. TB was negative and then peritoneal biopsy was done. The second case was a 40- year- old man with hoarsness, cough and hemoptysis for 6 years. Not only smear for M. TB was positive but also in laryngoscopy he had tumoral lesions. This lesions was positive for TB in pathologic test. Examination of these two methods showed that the best diagnostic method for TB peritonitis is biopsy and in laryngeal involvement sputum smear is usually positive but for confirming the diagnosis biopsy is suggested