Apigenin, a bioflavonoid, is abundantly present in fruits and vegetables and possesses potential chemopreventive properties against a wide variety of chronic diseases. In this study we investigated the anti-genotoxic effects of apigenin against a known genotoxicant, benzo(a)pyrene (B(a)P) (125 mg kg(-1) orally) toxicity in Swiss albino mice. B(a)P administration led to induction of cytochrome P-450 (CYP), aryl hydrocarbon hydroxylase (AHH) and DNA strand breaks (P < 0.001), which was suppressed by apigenin (2.5 and 5 mg kg(-1) orally) dose dependently (P < 0.001). B(a)P-induced depletion in the level of reduced glutathione (GSH), quinone reductase (QR) and glutathione-S-transferase (GST) was also shown to be restored by apigenin pre-treatment (P < 0.001). A simultaneous significant and dose-dependent reduction was noted in DNA strand breaks and in-vivo DNA damage (P < 0.001), which gives some insight into restoration of DNA integrity in modulator groups. These results strongly support the protective nature of apigenin against B(a)P-induced toxicity.