The effects of sex and season on metal levels of the mantle of the common cuttlefish that was caught from Mersin Bay were evaluated. The annual range of mantle length (ML), total length (TL), and weight of common cuttlefish specimens were 110 to 183 mm, 380 to 581 mm, and 150.24 to 477.13 g, respectively. The annual range of metal levels in the mantle tissue of common cuttlefish were: 2.34 to 3.89 mu g Cd g-1, 0.30 to 0.63 mu g Cr g-1, 0.15 to 0.54 mu g Pb g-1, 2.35 to 14.90 mu g Cu g-1, 23.22 to 51.88 mu g Zn g-1, and 5.12 to 10.65 mu g Fe g-1. Cu levels of females were significantly higher (P < 0.05) than those found in male throughout all the seasons while Pb levels were lower (P < 0.05) in males than females. Cr levels in the mantle tissue of cuttlefish did not change throughout the seasons. On the contrary, Cd, Pb, Cu, Zn, and Fe levels in the mantle tissue of cuttlefish changed throughout all the seasons. The highest Cd, Zn, and Fe levels were obtained in spring while the highest Cu levels were obtained in autumn. It was also found out that this species was rich in terms of metal levels, particularly, Cd, Cu, Zn, and Fe. It was found out that the mantle tissue of the common cuttlefish, Sepia officinalis, which was caught from Mersin Bay, was contaminated with Cd in all the seasons.