(1) Background: High-intensity gait training (HIT) is a recommended intervention that improves walking function (e.g., speed and distance) in individuals who are undergoing stroke rehabilitation. This study explored clinicians’ perceived barriers and facilitators to implementing HIT utilizing a mixed-methods approach comprising a survey and exploratory qualitative research. (2) Methods: Clinicians (n = 13) who were implementing HIT at three facilities participated. We collected and analyzed data using the consolidated framework for implementation research. Three focus groups were recorded and transcribed, and data were coded and thematically categorized. (3) Results: Survey results identified that the facilitators with a strong impact on implementation were access to knowledge/resources and intervention knowledge/beliefs. The only agreed-upon barrier with a strong impact was lack of tension for change. The focus groups resulted in 87 quotes that were coded into 27 constructs. Frequently cited outer setting facilitators were cosmopolitanism and peer pressure, and the only barrier was related to the patient needs. Innovation characteristics that were facilitators included relative advantage and design quality and packaging, and complexity was a barrier. Inner setting facilitators included networks and communication, learning climate, leadership engagement, and readiness for implementation. However, communication, leadership engagement, and available resources were also barriers. Regarding characteristics of individuals, knowledge and beliefs were both barriers and facilitators. In the implementation process domain, common facilitators were formally appointed implementation leaders and innovation participants. Barriers in this domain were related to the patients. (4) Conclusions: Clinicians identified many barriers and facilitators to implementing HIT that often varied between facilities. Further research is warranted to deepen our understanding of clinicians’ experiences with HIT implementation.
