Background: Radiation oncology peer review involves presentation of new cases including pertinent patient history and case-specific qualitative treatment planning decisions. Yet implementation of peer recommendations is inconsistent. Thus, we sought to understand multidisciplinary perspectives on peer review to identify factors affecting stakeholder engagement. Methods: Participants in radiation oncology peer review completed semi-structured interviews and Likert surveys to explore the perceived value in peer review and its influence on their clinical practice and plan changes. Interviews were audio-recorded and transcribed, and two independent coders utilized a grounded theory approach to extract dominant themes. ANOVA and students t-test were used to analyze Likert scores. Results: Participants included 6 academic and 3 community radiation oncologists, 2 radiation oncology residents, 2 medical physicist, 2 radiation therapists, 4 dosimetrists and 1 industry representative. Analysis of interviews regarding perceived priorities of peer review revealed the following themes: understanding the clinical background to inform decision-making, detection of rare errors not found in other quality assurance processes, coherence in practice within an organization, and education on new techniques. Key facilitators included pre-planning communication between multidisciplinary teams, particularly for replanning and reirradiation scenarios. Barriers to adaptation of recommendations included resource limitations and lack of supporting data. Likert surveys (0=no importance, 10=highest importance) assigned a high value to the overall process (mean score: 8.3), reducing variation in practice (8.0), conformity of plans with institutional guidelines (7.8), and participant education (7.6), with a lower value placed on the detection of medical errors (7.4) and reduction of treatment incidents (6.9). When comparing Likert scores by provider, non-physicians rated overall importance of peer review (mean: 9.8 vs 6.5, p=0.03) and education (9.0 vs 6.7, p=0.02) significantly higher than physicians. There was no significant difference in Likert scores by academic vs community practice. Conclusions: All participants agreed peer review is an important process in radiation oncology quality assurance that may catch rare errors. However, there was significant variation in the perceived benefits of peer review, and a higher value was placed on alignment of clinical practice and non-physician participant education. Future processes to improve communication between multi-disciplinary teams was identified as beneficial to peer review discussions.