The aim of this research was to examine the effect of group counseling based on psychodrama approach on peer relationships of female adolescents. 38 girl students from high school junior level participated in the research; 21 of these were in the experimental group and 17 were in the control group. "Peer Relationship Scale" and "Personal Information Form" were used for data collection. The research was a semi-experimental study based on the model with pretest, post-test and follow-up tests on the experimental and control groups. Psychodrama group application for experiment group has lasted for 16weeks, 180 minutes once a week. In the meantime, no study was conducted with the control group. Data obtained from pre-test, post-test and follow-up tests were tested by "Two- Way ANOVA for Mixed Measured" which is suitable for mixed designs. Findings have illustrated that the students' commitment, trust, self-disclosure and loyalty scores in the experiment group have increased significantly when compared to the control groups. It has been observed in the follow up test that increasing commitment, trust, self-disclosure and loyalty in scores has not lasted for three months.