Linezolid is identified as an effective drug with which to treat patients failing multidrug-resistant (MDR)-tuberculosis (TB) treatment. However, cost and safety are the concerns. In India, the average price of a 600-mg pill of linezolid is less than one US dollar, much cheaper than most of the third-line drugs. A prospective study of 29 MDR-TB treatment failure patients (16 with laboratory-proven extensively drug-resistant (XDR)-TB and the remaining 13 with MDR-TB with resistance to any quinolone but sensitive to injectables) was carried out in Delhi, India. All patients received daily unsupervised therapy with linezolid, one injectable agent, one fluoroquinolone and two or more other drugs. Patients received a median of six anti-mycobacterial agents. Besides linezolid, capreomycin, moxifloxacin, levofloxacin and amoxycillin-clavulanic acid were used in 41.4%, 58.6%, 41.4%, and 79.3% of patients. Out of a total of 29 patients, 89.7% patients achieved sputum smear and culture conversion; 72.4% showed interim favourable outcome; 10.3% died, 6.8% failed and 10.3% patients defaulted. Linezolid had to be stopped in three (10.3%) patients due to adverse reactions. The outcome of treatment of 16 XDR-TB patients was comparable to the other 13 MDR-TB patients. Linezolid is an effective, cheap and relatively safe drug for patients failing MDR-TB treatment, including those with confirmed XDR-TB.