Objectives: The aim of this investigation was to study alexithymia and its relationship with physical complaints, emotional competency and mood disorders in children and adolescents. Method: 593 (308 girls and 285 boys) elementary school children in the city of Shiraz were selected using multi-stage cluster sampling. Participants completed the Alexithymia Questionnaire for Children, Mood List for Children and Somatic Complaint List. The validity of the instruments was determined through calculating correlation between subscales with each other and the total scale, and reliability was determined using Cronbach’s alpha. Results indicated a satisfactory and high reliability and validity of the instruments used in this study. Data were analyzed using analysis of variance and regression analysis. Results: Alexithymia showed positive association with physical complaints and negative emotions, and negative association with happiness. Gender differences were also significant, and girls had higher scores averages in comparison with boys. Conclusion: Difficulty in identifying feelings and external oriented thinking had the highest and lowest predictive powers respectively.