The present study concerns the clinical appraisal of adverse reactions reported in the course of Rifampicin (RMP) treatment, reactions which have given rise to conflicting reports. The lot studied included 243 cases of pulmonary tuberculosis of which 57 were treated according to the 7/7 regime (600 mg RMP), 152 according to the 2/7 regimen (900-1200 mg RMP) and 34 according to the 7/7 followed by the 2/7 regimen. Tolerance to RMP was followed up by a series of adequate tests and close clinical surveillance. Adverse reactions developed in 31.5% to 41.5% of the cases in terms of the treatment scheme. In the intermittent treatment adverse reactions occurred in 17.1% of the cases.