Sodium monofluoroacetate (NAFAc) has been widely used for vertebrate pest control, such as rabbits in Australia. However, NAFAc is extremely toxic to all vertebrates and its use is restricted. Although this compound is stringently restricted, the occurrence of accidental and homicidal poisoning is na ever-present possibility. The method developed in this work shows the applicability of SPE with alumina cartridges for the extraction of NAFAc from serum samples. The method is efficient with recoveries of at least 96.8% from spiked serum. The samples were subsequently derivatized with dicyclohexyl-cabodiimide (DCC), using 2,4-dichloroaniline (DCA), to make the product volatile for GC analysis.