In 2007, a task-shifting strategy through which a nurse, in collaboration with a community pharmacist, could start a healthy woman on hormonal contraception without a medical consultation was implemented in the province of Quebec. The purpose of this study was to identify factors associated with the 1) implementation of this new practice by nurses, 2) delay of implementation and 3) intensity of the practice. A validated questionnaire based on Rogers' theory of the diffusion of innovation was sent by postal mail or internet to all nurses that had successfully completed training in hormonal contraception since 2007, were registered at the College of nurses of Quebec and currently worked as nurses. The questionnaire was completed by 745 nurses between November 2011 and March 2012 for a response rate of 26.6%. Results show that implementation of this new nursing practice was more successful when nurses had a high degree of cosmopoliteness, they perceived the new practice as simple, they worked in youth clinics and if health organizations where they worked were open to innovation, had low centralized decision-making and organizational slack. Various attributes of innovation, diffusion networks and characteristics of the organizations also explained intensity of the new practice. The findings suggest new avenues to simplify and scale up this strategy for use in other health organizations.