The reaction between chloramphenicol and chloramine-T, chloramine-B, bromamine-B or bromamine-T has been found to proceed quantitatively over a wide range of experimental conditions. Simple titrimetric procedures for the estimation of chloramphenicol with N-haloamines have been developed. Oxidation of the antibiotic involves a four-electron change and the products of oxidation have been identified. The methods are useful for the estimation of this antibiotic in medicinal formulations.