This paper briefly highlights the factors responsible for treatment failure in clinical practice. The author has limited his discussion to the factors related to the physicians and drugs. The factors which influence the outcome of anti-TB treatment are classified as “intrinsic” - those related to the patient and “extraneous” - those which are not directly related to the disease or the mycobacteria, but influence the treatment outcome.

Prescription errors and drugs confusion are two important factors responsible for failure of treatment of TB. Both these factors are potentially preventable if greater inputs are made in programmes related to physician’s education and drug rationalization.