Objectives: Mifepristone for first-trimester medical termination of pregnancy (MTOP) became available in Quebec in 2018, one year after the rest of Canada. Using the theory of the Diffusion of Innovation (DOI) and the transtheoretical model of change (TTM), we investigated factors influencing the implementation of mifepristone MTOP in Quebec.Material and Methods: Semi-structured interviews were conducted with 37 Quebec physicians in early 2018. Deductive thematic analysis guided by the theory of DOI explored facilitators and barriers to physicians' adoption of mifepristone MTOP. We then classified participants into five stages of mifepristone adoption based on the TTM. Follow-up data collection one year later assessed further adoption.Results: At baseline, three physicians provided mifepristone MTOP (Maintenance) and two were about to start (Action). Thirteen physicians at Preparation and Advanced Contemplation stages intended to start while, within the Slow Contemplation, two intended to start and ten were unsure. Seven had no intention to provide mifepristone MTOP (Pre-Contemplation). Major reported barriers were: complexity of local health care organisations, medical policy restrictions, lack of support, and general uncertainty. One year later, ten physicians provided mifepristone MTOP (including three at baseline) and nine still intended to, while seventeen did not intend to start provision. Seven of sixteen participants (44%) who worked in TOP clinics at baseline were still not providing MTOP with mifepristone one year later.Conclusion: Despite ideological support, mifepristone MTOP uptake in Quebec is slow and laborious, mainly due to restrictive medical policies, vested interests in surgical provision and administrative inertia.