An intracanal medicine is often required because microorganisms in the dentinal tubes may be difficult to eliminate completely by instrumentation. Phenolic compounds are widely used in dental treatment as sedatives for the dental pulp or as disinfectants for caries and the root canal. In this study, propidium iodide fluorescence and DNA precipitation assay were used to investigated the cytotoxic and genotoxic effects of camphorated phenol and camphorated parachlorophenol on cultured human pulp fibroblasts in vitro. Both medicines reduced the content of double-stranded polynucleic acid of fibroblasts over a 24-h culture period in a concentration-dependent manner. Camphorated parachlorophenol was more cytotoxic than camphorated phenol. But, both medicines did not cause genotoxicity on pulp cells. The advantage of these experimental methods are simplicity and rapidity. Furthermore, this experimental system may be useful for preliminary cytotoxicity and genotoxicity screening of various dental medicines in vitro.