BACKGROUND Global Doctors for Choice-a transnational network of physician advocates for reproductive health and rights-began exploring the phenomenon of conscience-based refusal of reproductive healthcare as a result of increasing reports of harms worldwide. The present White Paper examines the prevalence and impact of such refusal and reviews policy efforts to balance individual conscience, autonomy in reproductive decision making, safeguards for health, and professional medical integrity. OBJECTIVES AND SEARCH STRATEGY The White Paper draws on medical, public health, legal, ethical, and social science literature published between 1998 and 2013 in English, French, German, Italian, Portuguese, and Spanish. Estimates of prevalence are difficult to obtain, as there is no consensus about criteria for refuser status and no standardized definition of the practice, and the studies have sampling and other methodologic limitations. The White Paper reviews these data and offers logical frameworks to represent the possible health and health system consequences of conscience-based refusal to provide abortion; assisted reproductive technologies; contraception; treatment in cases of maternal health risk and inevitable pregnancy loss; and prenatal diagnosis. It concludes by categorizing legal, regulatory, and other policy responses to the practice. CONCLUSIONS Empirical evidence is essential for varied political actors as they respond with policies or regulations to the competing concerns at stake. Further research and training in diverse geopolitical settings are required. With dual commitments toward their own conscience and their obligations to patients' health and rights, providers and professional medical/public health societies must lead attempts to respond to conscience-based refusal and to safeguard reproductive health, medical integrity, and women's lives.