The aim of this study was to compare hematological, some biochemical parameters, and serum trace element concentrations in horses with or without pica. Fifteen horses with pica (group I) and another 15 healthy horses without pica (group II) were used. The hematological parameters were not changed between the two groups. In group I, hemoglobin values were lower than those of group II. However, the difference in hemoglobin values between the two groups was not significant (P > 0.05). Serum iron and copper concentrations and the copper/zinc ratio were lower in group I than those of group II (P < 0.05). The other biochemical parameters were not found to be statistically different between the two groups (P > 0.05). It was concluded that serum iron and copper deficiency may play an important role for the etiology of pica in horses. Prophylactic use of iron and copper supplements in horses may be beneficial to prevent pica.