The Brazilian World Health Survey, carried out in 2003, included questions about diagnosis of six chronic diseases: arthritis, angina, asthma, depression, schizophrenia and diabetes mellitus. The probabilistic sample of 5,000 adults was selected in 250 census tracts. We analyzed the socio-demographic profile, the coverage of treatment, and self-rated health of the individuals that reported diagnosis of one of these diseases. To control for age and sex, logistic regression models were used. Among the 5,000 participants, 39.1% reported medical diagnosis of at least one of the six diseases. Depression was the most prevalent (19.2%), followed by asthma (12.0%), arthritis (10.5%), angina (6.7%), diabetes (6.2%) and schizophrenia (1.7%). Significant differences by age were found for all diseases, except for asthma. All diseases were more prevalent among women, except angina. Analysis by educational level showed that the diabetes prevalence rate was significantly larger among those with incomplete schooling. Although the six diseases presented different treatment coverage rates, for individuals with diagnosis of any one of the six diseases, the self-rated health was always worst, even after controlling for age and sex.