Objective: To evaluates the frequency of development of hepatotoxicity in patients with tuberculosis on antituberculous treatment presenting in department of Medicine Liaquat University of Medical and Health Sciences Jamshoro. Methodology: This prospective, descriptive study was carried out on five hundred diagnosed patients with tuberculosis, during March 2008 to March 2011. In this study tuberculous patients were included who were consecutively admitted in department of medicine or attended medical out-patient department of Liaquat University of Medical and Health Sciences (LUMHS) Jamshoro. The patients, who developed hepatitis, while they were on antituberculous therapy, were evaluated. The criteria for diagnosing hepatitis were clinical manifestations of acute hepatitis along with rise in serum liver enzymes by three times from baseline and excluding other causes of rise in enzymes. In all patients who presented to us with acute hepatitis while on antituberculous therapy, sera were analysed for, liver function tests and the presence of markers of acute viral hepatitis A, B, C and E. The patients who developed viral hepatitis were excluded from study. Patients with tuberculosis who received the full course of antituberculous therapy without developing hepatitis formed the control group; they were compared with patients who developed hepatitis due to antituberculous therapy. Statistics: The results are expressed as the mean ± SD. For the comparison of quantitative data, the Student's t test was applied using SPSS 16. Values of p < 0.05 were regarded as significant. Results: The age of these patients ranged from 15 to 80 years, the mean age being 41.8 ± 17.6 years. The male-to-female ratio of these patients was 300(60%) males to 200(40%) females. Pulmonary tuberculosis was the most common definite indications for starting ATT Table-1. 55 patients (11%) out of 500 developed ATT-induced hepatitis. Five (1%) patients with antituberculous treatment induced hepatitis died Table 2. The mean age of patients with fatal complications in our study was 50.1±3.5 years. The values of various liver function tests during follow-up are shown in Table 3. Conclusion: It was concluded that ATT-induced hepatitis is not an uncommon problem in field of Medicine.