Introduction: Tuberculosis (TB) is a communicable disease that is a major cause of ill health and one of the leading causes of death worldwide. Several socio-demographic factors contributing towards the increasing incidence and development of TB are age, gender, socioeconomic status, smoking, alcoholism, drug addiction, living conditions, literacy, family history, overcrowding, poor sanitation, poor ventilation, malnutrition, occupation. Primary Objectives: To evaluate the socio-demographic profile and body mass index (BMI) of patients with pulmonary tuberculosis and their treatment outcome. Secondary Objectives: 1. To assess the relationship between low SES and new smear positive PTB. 2. To assess malnutrition among diagnosed PTB patients. 3. To know how malnutrition and low SES affect the treatment outcome 4. To assess nutritional status of patients before and after treatment 5. To evaluate the relationship between co morbidity and treatment outcome. Methods: This is a prospective study done in 360 new sputum-positive pulmonary tuberculosis patients attending the department of respiratory medicine, GMC Kannur over 1 year. After full filling the inclusion and exclusion criteria data was collected and the results were organized and analyzed statistically. Results: The total sample size was 360. 29.2%, belonging to 41-50 years with the male preponderance of male: female ratio = 1.7:1. Regarding the socio-demographic profile, 93.3% were natives, and 72.2% were married. 81.9% belonged to the lower caste, 94.7% had nuclear families, with small-sized families of percentage 70, and most of them, 87.2% resided in pucca houses. The majority of cases had a primary level of education and the literacy rate was only 1.9%. 43.3% of Sputum-positive patients were from low SES. Malnutrition (BMI<18.5Kg/m2) was seen in 58% of patients and there was a significant increase in BMI (p< 0.001) after treatment completion. The majority of patients had DM (38.9%).There was statistically significant clearance in CXR after treatment completion (p <0.001). It was found that DM, smoking and CXR shadows can lead to reduced sputum smear conversion and it was statistically significant with statistical significance as follows: DM – OR=0.367,95%CI of OR is 0.181-0.742, p-value- .004, CXR shadows: OR=0.190,95% CI of OR- 0.079-0.460, p value-0.001, current smokers: p value-0.006. Conclusion: In the current study, the majority of patients was having undernutrition (BMI<18.5Kg/m2) and low SES. The nutritional status was improved after treatment completion. Sputum smear conversion at the end of 2 months, which is a key indicator of infectivity, was affected by patients smoking status, DM, and CXR shadow. Hence, education, awareness, smoking cessation, adequate nutritional support, DM control are necessary for control of TB and for achieving the national target.