Treatment of drug-resistant Mycobacterium tuberculosis infections requires combination of anti-tuberculosis drugs which have several toxic side effects. Thus there is a need for safer and effective new drugs. Ankaferd Blood Stopper (R) (ABS), which is a mixture of plant extracts prepared from Alpinia officinarum, Glycyrrhiza glabra, Thymus vulgaris, Urtica dioica and Vitis vinifera, has homeostatic and antibacterial effects. Standard solutions of ABS are already being used topically for post-traumatic and post-operative bleeding control in our country. This study was aimed to evaluate the in vitro activity of ABS against M.tuberculosis isolates. A total of 57 clinical isolates [17 multidrug resistant (MDR), 11 resistant to only isoniazid (INH), one resistant to INH and streptomycin (STR), two resistant only to STR, two resistant only to ETM, and 24 susceptible to all drugs] and three standard strains [H37Rv (susceptible to all drugs), ATCC 35822 (INH-resistant), ATCC 35820 (SIR-resistant)] were included in the study. Agar dilution method was used to detect the MIC values of ABS. In the study, ABS MIC value was determined as 10.94 mu g/ml for M.tuberculosis H37Rv strain which was susceptible to all antituberculosis drugs, whereas it was determined as 21.88 mu g/ml for INH-resistant ATCC 35822 and SIR-resistant ATCC 35820 strains. The MIC values for 24 susceptible clinical isolates were as follows; 10.94 mu g/ml (n= 17), 21.88 mu g/ml (n= 6) and < 1.37 mu g/ml (n= 1). When evaluating 17 MDR clinical isolates, MIC values were determined as 5.47 mu g/ml (n= 1), 10.94 mu g/ml (n= 5) and 21.88 mu g/ml (n= 11). MIC values were ranging between < 1.37-21.88 mu g/ml among 11 INH-resistant isolates. These isolates were susceptible to other first line anti-tuberculosis drugs. MIC value of one isolate resistant to both of INH and SIR was determined as 21.88 mu g/ml. MIC value of the two sole STR-resistant isolates was 21.88 mu g/ml. MIC values of the two sole ETM-resistant isolates were determined as 21.88 mu g/ml and 10.94 mu g/ml. MIC,c, and MIC90 values for the tested bacteria were 10.94 mu g/ml and 21.88 mu g/ml, respectively. It was concluded that 16 fold diluted concentration of the topically used ABS solution was found to be active against tuberculosis bacilli in vitro. Thus ABS might be used as a supportive agent together with anti-tuberculous drugs during debridement of multiple drug-resistant M.tuberculosis caused osteomyelitis and lymphadenitis lesions.