The purpose of the present study was to investigate the therapeutic effect of magnetic fluid hyperthermia (MFH) induced by an alternating magnetic field (AMF) on human carcinoma A549 xenograft in nude mice. An animal model of human lung cancer was established by subcutaneous injection of human lung cancer A549 cells in BALB/c nude mice. The xenograft mice were randomly divided into four groups and each group was treated with an injection of a different concentration of magnetic fluid: control, low-dose (67.5 mg/ml), medium-dose (90.0 mg/ml) and high-dose group (112.5 mg/ml), respectively. Following the injection (24 h), the tumor was heated in an AMF for 30 min. Tumor volumes were then measured every week. The therapeutic effect was assessed by measuring the tumor volume and weight. Pathological examination was performed with a light and electronic microscope following treatment. The temperature at the surface of the tumor in the low-, medium- and high-dose groups increased to 41.3, 44.5 and 46.8°C, respectively. The tumor grew significantly slower in the medium- and high-dose groups (both p<0.05) compared to the control group. Cytoclasis and apoptosis were detected under light and electron microscopy. In conclusion, MFH induced by AMF inhibited tumor growth and promoted apoptosis of human carcinoma A549 cells in a xenograft mice model.