Infections caused by drug-resistant Mycobacterium tuberculosis strains represent a serious public health problem in recent years. The aim of this retrospective study was to investigate the resistance rates of M. tuberculosis complex strains isolated from clinical specimens in the laboratories of Cumhuriyet University and Numune State Hospitals in Sivas province (located in the middle Anatolia), between May 2004-May 2006 period, to the major antituberculous drugs. A total of 158 M. tuberculosis complex strains which were isolated from sputum, bronchial lavage fluid, stomach fluid, urine, pus, peritoneal fluid and cerebrospinal fluid samples, each of which from different patients were included to the study. The identification of the isolates and antituberculosis drug susceptibility testing were performed by MGIT (Mycobacteria Growth Indicator Tube) 960 system in both of the laboratories. Of 158 isolates 42 (26.6%) were found resistant to at least one of the drugs, while 116 (73.4%) were susceptible to all of the tested antimycobacterials. The overall resistance rates were found as 17.7% (28/153) for isoniazid, 11.4% (18/153) for streptomycin, 4.4% (7/153) for rifampicin, and 5.1% (8/153) for ethambutol. The rate of multidrug resistant isolates characterized with resistance to isoniazid+rifampicin were 3.8% (6/158). As a result, the most common resistance patterns observed in our region were found as single isoniazid resistance (13/158; 8.2%), single streptomycin resistance (8/158; 5.1%) and combined isoniazid+streptomycin resistance (8/158; 5.1%), respectively, with lower resistance rate to rifampicin (4.4%) in comparison to the previous results reported from Turkey.