This cross-sectional study aimed to analyze the first health service to which patients turned for tuberculosis diagnosis in São José do Rio Preto, São Paulo, Brazil, 2009. Eighty-one patients in treatment were interviewed with a questionnaire based on the Primary Care Assessment Tool adapted to TB care and used as a reference for health services performance (structure and process). Data analysis used descriptive and multiple correspondence techniques. Nearly half of the patients initially came to emergency care departments (49.4%), and most TB diagnoses were made in hospitals (39.5%) and primary care services (30.9%). Specialized services were associated with the best diagnostic performance, as opposed to emergency departments, with the worst performance. Primary care services were associated with intermediate performance and weaknesses in infrastructure. The reach of effective detection of TB cases in the portals of entry into the health system involves enhanced diagnostic suspicion, thus emphasizing the need for investments in the management of human resources training for the identification of individuals with respiratory symptoms.