Rapid detection of drug-resistant tuberculosis (TB) has become increasingly important in the era of pandemic human immunodeficiency virus infection and antibiotic resistance. The identification of the molecular correlates of antibiotic resistance in Mycobacterium tuberculosis have engendered the development of DNA-based assays for the identification of drug-resistant TB. This review summarizes the recent discoveries concerning resistance to isoniazid, rifampin, pyrazinamide, ethambutol, streptomycin, amikacin, kanamycin and the quinolones.