Suboptimal hematological status has been often recorded in athletes involved in intense physical activity, particularly in middle and long distance runners. It appeared therefore interesting the study and comparison of athletes groups of different sports. One hundred eighty-one male athletes were tested and divided into seven groups according to sport exercise: cross-country skiing, cycling, fencing and tennis (joined together), rowing, running, soccer, swimming. For every athletes erythrocyte and hemoglobin blood concentration, hematocrit, serum iron, transferrin, ferritin and haptoglobin concentration were measured, the mean cell volume and serum iron/transferrin ratio were calculated. Data were compared to find out correlation indices and then grouped according to the practised sport. Statistical indices were computed for each group and for all parameter and analysis of variance was carried out to value the significativity of found differences. The only parameter showing statistically significant differences among groups was the serum level of haptoglobin, with mean value significantly lower in runners. The evidence of this study suggests that individual variability for the remaining parameters exceeds any variation possibly induced by different sport practices.