We established a practical and reliable method for rapid and simple analysis for butyrophenones in human hemolyzed blood by LS/MS/MS. Removal of hemoglobin and other large proteins from hemolyzed blood was simply completed using Amicon Ultra-4 centrifugal filter device (MILLIPORE). Six kinds of butyrophenones used in this research were detected with high sensitivity by LC/MS/MS. The detection limit in human hemolyzed blood was about 5 ng/ml except for timiperone and pimozide.