The Australian Mycobacterium Reference Laboratory Network collected and analysed laboratory data on new cases of disease caused by Mycobacterium tuberculosis complex in the year 2004. A total of 787 cases were identified by bacteriology, representing an annual reporting rate of 3.9 cases per 100,000 population. Almost all isolates were identified as M. tuberculosis (n = 785), the remaining isolates being one each of Mycobacterium africanum and Mycobacterium canettii. Seven children under 10 years of age (female n = 5, male n = 2) had bacteriologically confirmed tuberculosis (gastric aspirate n = 4, lymph node n = 1, pleural n = 1, thigh wound n = 1). Results of in vitro drug susceptibility testing were available for all 787 isolates for isoniazid (H), rifampicin (R), ethambutol (E), and pyrazinamide (Z). A total of 71 (9.0%) isolates of M. tuberculosis were resistant to at least one of these anti-tuberculosis agents. Resistance to at least both H and R (defined as multidrug resistance) was detected in 12 (1.5%) isolates; 10 were from the respiratory tract (sputum n = 7, bronchoscopy n = 3). The country of birth was known for 68/71 (95.8%) cases with a drug resistant strain; eight were Australian, 60 were overseas born, and three were unknown. Of the 60 migrants with drug resistant disease, 37 (61.7%) were from three countries; Viet Nam (n = 20), China (n = 9) and India (n = 8).