SETTING: The study was conducted within a nation-wide population-based tuberculosis (TB) prevalence survey in the adult population in Tanzania. OBJECTIVE: To assess the health care-seeking behaviour of coughers presumed to have TB. DESIGN: A survey in which participants were screened for TB using a symptom questionnaire and chest X-ray (CXR). Those with cough of ⩾ 2 weeks and/or who were coughing blood were interviewed about their health care-seeking behaviour and socio-demographic and clinical factors. RESULTS: Of 3388 people with presumptive TB, 31.0% (1051/3388) had sought treatment for their symptoms. Of these, about 42% (445/1051) sought care at sites with TB diagnostic capacity, where sputum examination was performed in 37.1% (165/445) and CXR in 28.1% (125/445). In sites with limited TB diagnostic capacity, fewer than 1% were referred for sputum examination or CXR. Individuals with additional symptoms were more likely to seek treatment. Knowledge about TB was significantly associated with care seeking at sites with TB diagnostic capacity. CONCLUSIONS: A third of the persons with cough symptoms consistent with TB had sought health care. About 42% sought care in sites with TB diagnostic capacity, but most did not undergo TB diagnostic procedures, precluding a timely diagnosis.