Introduction: Motivational interviewing (MI) is an evidence-based counseling approach within primary care. However, MI rarely translates to practice following introductory training programs, and a lack of evidence regarding its implementation persists today. This study describes primary care clinicians' professional transformation in implementing MI through interprofessional communities of practice (ICP-MI). Method: Qualitative data collection involved the research journal, participant observation of four ICP-MIs (76 hours/16 clinicians), and focus groups. A general inductive approach was used for data analysis. Results were conceptualized based on the Consolidated Framework for Implementation Research. Results: Four processes of MI implementation in primary care are presented as a motivational endeavor: ambivalence, introspection, experimentation, and mobilization. The clinicians were initially ambivalent, taking into consideration the significant challenges involved. After introspecting actual practices, they realized the limits of their previous clinician-centered approaches. The experimentation of MI in the workplace followed and enabled clinicians to witness MI feasibility and its added value. Finally, they were mobilized to ensure MI sustainability in their practices/organization. Intrinsic factors of influence included the clinicians' personal traits and their perception about MI as a clinical priority. Organizational support was also a crucial extrinsic factor in encouraging the clinicians' efforts. Conclusion: As described in a fragmented manner in previous studies, MI implementation processes and influencing factors are presented as integrated findings. Incorporating engaging educational activities to provide clinicians with motivational support and collaborating with health care organizations to plan appropriate resources should be considered in the development of MI implementation programs from the onset.