The chemical composition, minor and major elements concentration and microstructure of juvenile and adult shells of Sepia officinalis were investigated by using electron X-rays and scanning electron microscope. The results generally showed significantly higher metal concentration in the juvenile shell than in the adult one, except calcium and aluminum. However, the highest accumulation was for copper, lead, and cadmium. The relationships between metal concentration and shell length, weight, and position were determined.However, no relationships between heavy metals pollution and microstructure of the shells of the investigated cephalopod were observed.