Over three quarters of the 8 million registered doctors in India are engaged in private medical practice. In urban and rural areas alike people prefer private doctors to public health services for their health care needs. A majority of patients and those with suspected tuberculosis also report first to private doctors. Nevertheless private doctors seem to be alienated from national efforts towards control of tuberculosis, there being no well-defined role for them in the National Tuberculosis Programme. This study of private doctors practising in the low income areas of a metropolis of India reports on the knowledge of private doctors about diagnosis and treatment of tuberculosis and their awareness and perceptions about the public health services available for tuberculosis control. The study reveals gaps and weaknesses in the private doctors' reported practice of managing lung tuberculosis, the most important and persistent problem of public health concern in India. The need for organized efforts towards involving private doctors in disease control programmes wherein their curative functions could contribute significantly is stressed.