The Society of Obstetricians and Gynaecologists of Canada has played a leadership role in advancing patient safety at the national level with the launching of their obstetric patient safety program 'Managing Obstetric Risks Efficiently' (MORE(OB)). Developed over a 2-year period and launched as a pilot in 2002, the program has extended to 126 hospitals in five provinces that provide care for 48% of the births in Canada. The end-point for the program is to change the culture of blame to a focused and sustained patient safety culture, where patient safety is everyone's responsibility, with observed reductions in events and improved quality of care. The program has integrated the principles of high reliability organizations (HROs), systems error theory, team function, and communities of practice (CoPs) as values for the work environment. In this chapter we describe how the program was developed, the role of the national specialty society in the development, and the funding, structure and implementation of the program, and we report on the impact of the program over the first 3 years. In these first 3 years, knowledge enhancement in all disciplines and in all practice environments, with a significant reduction in variance among the disciplines, has been demonstrated. Culture change has occurred in all practice settings and has continued to improve over time. Using liability claims information from the hospitals, a reduction trend has been observed in liability carrier (hospital) incurred costs.