This study examined the effect of Discrimination Model (DM)-based group supervision on novice supervisees' counseling self-efficacy and insight levels. The study used a pretest-posttest model with 3X2 quasi-experimental, comparison, and control groups. Eighteen novice supervisees (6 participates in each group) constituted the participants. Two-factor ANOVA for mixed designs/split-plot tests was performed to analyze the data. The results revealed that DM-based group supervision significantly increased the levels of Helping Skill Self-efficacy (HSS), Session Management Self-efficacy (SMS), Counseling Challenges Self-efficacy (CCS), and Insight of novice supervisees. The comparison group showed significant changes only in their HSS and SMS levels, but not in their CCS and Insight levels. The results revealed that DM-based group supervision led to a significant difference in novice supervisees' SMS, CCS, and Insight levels compared to the comparison group. However, there was no significant difference between the two groups in terms of their HSS levels. Moreover, the control group did not score differently regarding the research variables. DM-based group supervision is an effective way for novice supervisees to develop counseling self-efficacy and insight. Findings provide an empirically-based clinical map for those aiming to provide effective supervision.