Background: Tuberculosis (TB) remains as an important public health problem in India. Awareness about the disease, its diagnosis, and treatment among public will help in controlling the killer disease. This study aims at arriving at an educational diagnosis about TB in an urban poor community. Materials and Methods: A cross-sectional study was conducted in an urban slum in South India using a structured, pretested questionnaire. Domains identified were knowledge about TB, symptoms, spread, diagnosis, treatment, and prevention of TB. Results: A total of 395 households were interviewed. Of them, 370 (94%) respondents had heard about TB. Regarding the symptoms of TB, 82% were aware that cough is a symptom of TB. Among the 79% of study subjects who reported any test to diagnose TB, sputum examination as a method of diagnosis was known to only 40%. However, 84% of the subjects were aware of the free treatment available for TB under National program. Conclusion: Level of awareness about TB among urban poor in a slum area is good. Knowledge about "free treatment" and "duration of treatment" has to be stressed during health education activities.