Several risk factors have been identified of becoming ill of tuberculosis. This article estimates the importance of risk groups associated with tuberculosis within the Metropolitan Region of Chile in 2008. The incidence rate of tuberculosis for the Metropolitan Region was 14.19 per 100.000 inhabitants, being much higher in people with HIV (380,5), in homeless people (218. 7), in convicts (213.4), contacts of tuberculosis patients (104.5) , foreigners (37.5) and in elderly people (32.8). All of these risk groups have a significant association with tuberculosis and their odds ratios ranged from 29 (HIV) to 2.6 (elderly people). In spite of being few cases, the risk of becoming ill of tuberculosis in people belonging to risk groups such as HIV, homeless, convicts and foreigners is higher in comparison with the rest of the population. The elderly people also have a risk higher than the rest of population, representing 18.8% of the tuberculosis cases in the region.