BackgroundChildren suffering from thalassemia have higher levels of depression and lower levels of self-concept.ObjectivesThe aim of this study was to determine if group play therapy could significantly increase self-concept among children with thalassemia major ages 7 to 11 years old in teaching hospitals of Golestan province, Iran, in 2012.Patients and MethodsIn this randomized, controlled clinical trial, 60 children with thalassemia major were randomly assigned to intervention (30 children) and control (30 children) groups. The intervention included eight 45 to 60 minute sessions during four weeks, during which the intervention group received group play therapy. The control group received no interventions. Self-concept was measured three times using the Piers-Harris children’s self-concept scale: before, immediately after, and a month after the intervention.ResultsFor the intervention group, results showed that the mean self-concept score was significantly higher at the second point in time compared to the baseline (P < 0.001), going from 60.539 to 69.908. Likewise, comparing the first and third time points, the mean score significantly increased and reached 70.611 (P < 0.001). Furthermore, changes in the mean score from the second to the third time point, though non-significant (P = 0.509), followed the trend, going from 69.908 to 70.611. For the control group, comparing the first, second, and third time points did not result in any significant change in the mean score (P > 0.05).ConclusionsThe results showed that group play therapy improves self-concept in children suffering from thalassemia major.