Patients with multiresistant tuberculosis (TB) and patients with intolerance of first line antituberculosis drugs present a major treatment problem. Sparfloxacin is highly active against mycobacteria, but the use is restricted by side effects and the contribution to antituberculosis therapy is unclear. A prospective study has therefore been performed to analyse the efficacy and tolerability of sparfloxacin in cases of resistant TB or intolerance of first line therapy.Between April 1993 and April 1999, 30 TB patients (28 with pulmonary TB and two with lymph node TB) were treated with combinations of sparfloxacin and at least two other drugs at the Chest Hospital Heckeshorn, Berlin. Sixteen patients were infected by resistant mycobacteria (one single drug resistance (SDR), one polyresistance, and 14 multidrug resistances (MDR); 14 males (age range 23–53 yrs), 2 females (68–74 yrs)). Twelve patients (11 males, one female, 27–80 yrs) had not tolerated first line antituberculosis drugs. Two additional male patients had continuous proof ofMycobacterium tuberculosisin sputum without resistance during therapyThe duration of sparfloxacin therapy during hospitalization ranged 2.5–4 months. Twenty-five patients completed therapy and were cured according to this study's definition. Although sparfloxacin was generally well tolerated, five mild phototoxic reactions and six moderate prolongations of the electrocardiographic QT-interval (30–40 ms compared to baseline ≤450 ms) were registered without clinical symptoms in the patient group.In summary, sparfloxacin proved an effective and safe alternative antituberculosis drug for complicated tuberculosis.