The purpose of the study was the objective evaluation of the mucolytic and antibiotic properties of Fluimucil® Antibiotic, a molecular combination of acetylcysteine and thiamphenicol. The preparation was administered to 45 patients in the dose of 3 tablets daily each containing 500 mg of thiamphenicol. Statistical analysis of the data obtained showed mucolytic effects on the 4th to 5th day of treatment and a marked antibiotic activity. The evaluation is positive particularly if the relatively low dose of antibiotic normally used in chronic bronchitis is considered. The preparation Fluimucil Antibiotic can be recommended for the treatment of chronic bronchitis also in view of its good tolerability