The combination of chlorhexidine digluconate and EDTA produces a white precipitate. The aim of this study was to determine if the precipitate involves the chemical degradation of chlorhexidine digluconate . The precipitate was produced and redissolved in a known amount of dilute trifluoroacetic acid. The amount of chlorhexidine digluconate and EDTA present in the dissolved precipitate was determined by reverse-phase high performance liquid chromatography (HPLC) with ultraviolet detection at 288 nm. More than 90% of the precipitate's mass was found to be EDTA or chlorhexidine digluconate . The remainder is suspected to be water, gluconate, and sodium. Parachloroaniline, a potentially carcinogenic decomposition product of chlorhexidine digluconate ,was not detected in the precipitate (the limit of detection was 1%). The molar ratio of chlorhexidine digluconate . to EDTA in the precipitate was about 1.6 to 1. Based on the results, chlorhexidine digluconate  forms a salt with EDTA rather than undergoing a chemical reaction.