Absorption spectroscopic studies of Congo red (CR) in interaction with FeCl3 in aqueous medium have been reported in this article. The interaction of CR with FeCl3 has been investigated with an aim to explore a possible low cost and efficient way to remove CR from industrial waste water. The removal mechanism is based on the formation of a complex of iron with anionic part of the CR molecule in interaction with FeCl3. An exceptionally high removal rate of 2670 mg/g has been observed at 100 mg/L initial CR concentration and enhanced removal rate was found with increasing initial CR concentration.