The disposition of clofoctol was determined in plasma and lung tissue from 34 patients undergoing pulmonary resection for lung cancer. Clofoctol 1.5 g was given as a rectal suppository; samples of plasma and pulmonary tissue were collected between 15 and 270 min post-dose. Plasma and lung peak concentrations of the drug were 38.07±0.73 mg/l and 93.13±6.68 mg/kg at 30 and 90 min, respectively. Mean values for areas under the concentration-time curve and half-life for plasma and lung were 80.91 mg/l/h, 229.65 mg/h, and 1.18 h and 1.21 h, respectively. Tissue to plasma ratios were 0.85±0.06, 3.82±0.21 and 6.19±0.63 at 30, 90 and 180 min post-dose, respectively. Clofoctol is well-absorbed from the rectum and accumulates in lung tissue. This may explain its efficacy in bacterial respiratory infections.