It is well known that methamphetamine is a neurotoxic drug of abuse to cause cell death both in vitro and in vivo. In this study, the protective effect of nerve growth factor on methamphetamine-induced neurotoxicity was examined in R2 cells. Treatment of R2 cells with methamphetamine for 48 h induced apoptotic-like death as determined by cell viability assay, DNA fragmentation on agarose gel and flow cytometric analysis. Co-treatment of R2 cells with nerve growth factor (10-1000 U/ml) in the presence of methamphetamine increased cell viability, decreased the intensity of methamphetamine-induced DNA fragmentation and reduced the number of apoptotic cells with flow cytometry. These results indicate that nerve growth factor may be useful for the treatment of methamphetamine users.