['Ho Chi Minh City, Vietnam.', 'To determine treatment outcome among patients treated by private lung specialists in a public-private mix (PPM) project for improved TB control.', 'Cohorts of patients treated by private lung specialists within the PPM project and in National Tuberculosis Programme (NTP) facilities were followed for up to 12 months. The quality of case management and treatment outcome was determined based on information in treatment cards. As a complement, questionnaire surveys of private providers (PPs) and patients and focus group discussions with PPs were conducted.', 'Among 400 patients treated by PPs, 36 different treatment regimens were used. Directly observed treatment was not used at all, and treatment evaluation with sputum smear microscopy and health education was inadequate. Overall treatment success was 60% and the default rate was 37%, which was considerably worse than in NTP facilities.'] Does treatment result among tuberculosis patients treated by private lung specialists involved in a public-private mix project in Vietnam?