Twenty-nine patients with extensive pulmonary tuberculosis and drug-induced hepatitis were treated with ofloxacin along with other relatively non-hepatotoxic drugs, either during the interim phase to await recovery of liver function in some, or as definitive therapy as required by the compromised hepatic status of others. No adverse drug reactions were noted and no treatment failures were observed. This preliminary experience indicates the exceedingly good tolerance of ofloxacin when utilized in treatment of extensive pulmonary tuberculosis in the face of deranged liver function tests. Due to the small number of patients and numerous variables, no definite conclusion can be drawn on the specific efficacy of ofloxacin against Mycobacterium tuberculosis. However, it is concluded that acquisition of further clinical experience is warranted for similar patients.