Linezolid (LZD) is classified as a WHO group 5 drug used in the treatment of tuberculosis (TB). Although its efficacy and long-term safety have not yet been established, it is being increasingly used in the treatment of multidrug resistant tuberculosis (MDR-TB) and extensive multidrug-resistant tuberculosis (XDR-TB). The current study is a single-center retrospective clinical analysis of hospitalized M/XDR-TB patients in Fukujuji Hospital involving 26 patients (18 men and 8 women) consecutively treated with combinations of anti-TB drugs including LZD from 2009 to 2015. The sputum culture results were negative after using LZD for an average period of 28.0 ± 12.0 (average ± SD) days. LZD was reduced or withdrawn in 11 cases due to adverse effects. Nineteen cases including 3 XDR-TB patients were operated on, and their TB was treated following surgery. The average time from the initiation of LZD therapy to surgery was 87.6 ± 38.7 (average ± SD) days. Favorable clinical outcome was maintained in 23 surviving patients, while 3 patients died during treatment because of end stage cancer and aspiration pneumonia. Our study showed that LZD might be clinically effective in the treatment of M/XDR-TB patients in Japan.