Nutritional changes during and after TB treatment have not been well described.The objective of the study was to determine the evolution of body mass index (BMI), fat mass (FM) and lean mass (LM), initially and at 2 months of antituberculosis treatment.A prospective study was carried out in a university hospital in Tunis. Patients followed for pulmonary TB were included. BMI, MM and MG, measured by BIA were evaluated initially and at 2 months of antituberculosis treatment. Fifty-three patients were included. The mean age was 40.8 ± 14.9 years. The mean BMI was 20.1 ± 4.2 kg/m2. The initial values of MM and MG were 47.9 ± 9.4 kg and 10.1 ± 7.5 kg respectively. After 2 months of anti-tuberculosis treatment, there was a significant improvement in BMI, MM and MG. The improvement of all parameters was lower in patients with more symptomatic, extensive radiological involvement severe TB.In conclusion, during the intensive phase of TB treatment, patients significantly improved their weight, MM and MG.