Curcumin can decrease viable cells through the induction of apoptosis in human lung cancer NCI-H460 cells in vitro. However, there are no reports that curcumin can inhibit cancer cells in vivo. In this study, NCI-H460 lung tumour cells were implanted directly into nude mice and divided randomly into four groups to be treated with vehicle, curcumin (30 mg/kg of body weight), curcumin (45 mg/kg of body weight) and doxorubicin (8 mg/kg of body weight). Each agent was injected once every 4 days intraperitoneally (i.p.), with treatment starting 4 weeks after inoculation with the NCI-H460 cells. Treatment with 30 mg/kg and 45 mg/kg of curcumin or with 8 mg/kg of doxorubicin resulted in a reduction in tumour incidence, size and weight compared with the control group. The findings indicate that curcumin can inhibit tumour growth in a NCI-H460 xenograft animal model in vivo.