BACKGROUND: Although pulmonary tuberculosis is effectively controlled with 6 months or 9 months short course standard regimens, comparable numbers of treatment failures ensued because of inadequate treatment mainly due to patient's poor compliance. Indequate treatment with standard regimens during initial treatment may cause emergence of drug resistance and prolong the duration of chemotherapy. Also it may make the patient lesser compliant and finally increase the morbidity and the mortality. METHODS: A clinical study was done to evaluate clinical and bacteriological characteristics of 94 patients who were retreated for pulmonary tuberculosis. RESULTS: 1) 62 of the 94 patients were male and 32 patients were female. Mean age is 51 years old in male and 45 years old in female. 2) The extent of the disease on the chest radiograph was minimal in 10(11.1%) patients, moderate in 31(33.3%) patients, and far advanced in 52(55.6%) patients. 3) On sputum bacteriologic examination, 73(77.7%) patients were positive in sputum AFB smear and/or culture for Mycobacterium tuberculosis. 4) Results of drug sensitivity test performed in 42 patients showed that the resistance to one drug is in 9(20.5%) patients, two drugs in 18(40.8%) patients, and more than three drugs in 14(31.8%) patients. 5) Poor patient's compliance was the leading cause of the retreatment of pulmonary tuberculosis (43.6%) 6) Only 24(25.5%) patients of the 94 retreatment patients were successfully treated and 39 (41.6%) patients were dropped out during follow-up. CONCLUSION: We concluded that poor patient's compliance was the most important cause of treatment failure not only in primary treatment patients but also in retreatment patients. Primary treatment of pulmonary tuberculosis should be completed under strict monitoring of the patient because significant number of retreatment patients had multiple drug resistance and poor outcome.