Occupational stress and burnout adversely impacts mental health care staff well-being and patient outcomes. Mindfulness training reduces staff stress and may improve patient care. However, few studies explore mental health setting implementation. This qualitative study used focus groups to evaluate stakeholders' perceptions of organizational factors affecting implementation of an adapted version of Mindfulness-Based Stress Reduction (MBSR) for staff on adolescent mental health units. Common facilitators included leadership securing buy-in with staff, allocating staff time to participate, and quiet space for training and practice. Other facilitators were past staff knowledge of mindfulness, local champions, and acculturating staff with mindfulness through a non-mandatory training attendance policy. Common barriers were limited staff time to attend training sessions and insufficient training coverage for some staff. Staff also reported improved focus when interacting with adolescents and improved social cohesion on the units. We conclude that a mindfulness-based program for reducing occupational stress can be successfully implemented on adolescent mental health units. Implementation appeared to change the social context of the units, including staff and patient interactions. More broadly, our findings highlight the importance of environmental factors in shaping attitudes, diffusion of innovation, and acculturation of wellness program implementations.