This study evaluated the thickness and chemical composition of the precipitate formed by the interaction between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) used as endodontic irrigants. Teeth irrigated with NaOCl followed by CHX without an intermediate flush developed a thick orange-brown precipitate, whereas absolute alcohol prevented precipitate formation by removing residual NaOCl. Analysis confirmed the precipitate was an insoluble neutral salt containing chlorine in the para position of the benzene ring. The results suggest using absolute alcohol or saline/distilled water as intermediate flushes to minimize or prevent precipitate formation between NaOCl and CHX.