The present study tried to determine if there are differences between temperament dimensions of boys and girls between three to five years old. The sample includes 406 participants: 221 boys and 185 girls, from 9 pre-schools districts (Arequipa-Peru). The study was descriptive and correlational, trying to find the relationship between dimensions of temperament in boys and girls. The Buss and Plomin scale of temperament: emotionality, activity and sociability (shyness) (EAS), and a demographic card built by the researchers were used. Significant differences were found in favor of girls in the dimensions of sociability and activity. On the other hand, there are no significant differences in relation to the different ages of the participants.