Purpose Previous surveys of anesthesiologists showed that despite a strong interest in implementing environmentally sustainable anesthetic practices, less than a third do so. Qualitative understanding of the capability, opportunity, and motivational factors that influence “green” behavior will inform the design of effective interventions to promote environmentally sustainable practices in the operating room (OR). Methods We conducted 23 semistructured interviews with anesthesiologists, with data saturation achieved. Applying the Behavior Change Wheel, interview questions addressed “capability,” “opportunity,” and “motivation” determinants of behavior. Results Preference for sevoflurane and syringe reuse were most commonly cited as existing environmentally sustainable anesthetic practices. Several participants reported lack of knowledge and feedback as impediments to sustainable anesthetic practices. Reported physical barriers included inadequate recycling facilities and abundance of supplies. Interviewees also discussed the importance of habitual behavior in improving skill sets and reducing cognitive load required to perform environmentally sustainable practices. General awareness of environmental issues and aggregation of marginal gains were reasons for environmentally sustainable measures in the OR. Organizational practice and culture played a significant role in the propagation of sustainable anesthetic practices, with senior staff often carrying a greater influence. While the majority preferred a top-down approach to effect change, others favored the use of incentives. Conclusion This study provides insight into the factors that influence the adoption of environmentally sustainable practices in the OR. Measures to promote these practices include education and training, feedback on efforts, engagement of senior anesthetists as role models and for change management, environmental restructuring, and policy designs that balance a top-down vs bottom-up approach to influencing change. Supplementary Information The online version contains supplementary material available at 10.1007/s12630-022-02392-0.