Tuberculosis is a worldwide public health problem, which, even with available treatment, continues to cause deaths worldwide. One of the obstacles to control the disease is the multifactorial difficulty of patients to adhere to treatment, in addition to the difficulty of health workers in circumventing barriers to implement strategies such as the directly observed treatment (DOT). The aim of this study is to analyze the performance and challenges faced by health workers in the use of DOT in tuberculosis. This is a descriptive, quali-quantitative study using data from interviews with primary-care professionals working in nine municipalities of Parana State, Brazil. The professionals answered a questionnaire containing four closed questions about DOT and an open question related to their professional opinion about the strategy. Quantitative data were entered into a spreadsheet and statistically propagated. Qualitative data were treated from the transcription of statements, subsequently submitted to content analysis. Of the 387 professionals interviewed, at least 58.9% had some knowledge about DOT. Among the main challenges faced by the professionals are: lack of user commitment to treatment (48.3%), users' difficulty in attending the basic health clinics (BHC) (31.4%), professionals' difficulty to reach the place where patients are treated (8.8 %), insufficient staff / lack of human resources (4.1%) and use of illicit drugs by patients (3.9%). Blaming the user and the lack of resources are the main highlights, in addition to issues such as the professionals' lack of access and knowledge that are highlighted by the difficulty of patients to adhere to the treatment of tuberculosis according to the participants' statements. The issues were raised by health workers manifestations involving adherence to treatment according to the DOT in the studied health region. It is possible, in this context, to observe the need for improvement in the knowledge of professionals with regard to the DOT, the importance of their bond with patients and families and the recognition of the part of responsibility that belongs to the health team on guaranteeing treatment.