Simple, rapid, and accurate spectrophotometrc procedures for the determination of the antibiotic rifampicin, in capsules, are presented. A chelate formation of the antibiotic with cupric ion and charge-transfer complexation with halogenated quinones are carried out. Linear correlations between absorbance and concentration over the range of 40-100 μg ml−1 were computed. The reaction pathways were proposed. The utility of copper chelate as a stability indicating procedure as well as a method to determine rifampicin In spiked urine samples is demonstrated.