Unsafe abortion is one of the three leading causes of maternal mortality in low-income countries; however, few countries have reformed their laws to permit safer, legal abortion, and professional medical associations have not tended to spearhead this type of reform. Support from a professional association typically carries more weight than does that from an individual medical professional. However, theory predicts and the empirical record largely reveals that medical associations shy from engagement in conflictual policymaking such as on abortion, except when professional autonomy or income is at stake. Using interviews with 10 obstetrician-gynaecologists and 44 other leaders familiar with Ethiopia's reproductive health policy context, as well as other primary and secondary sources, this research examines why, counter to theoretical expectations from the sociology of medical professions literature and experience elsewhere, the Ethiopian Society of Obstetricians & Gynecologists (ESOG) actively supported reform of national law on abortion. ESOG leadership participation was motivated by both individual and ESOG's organizational commitments to reducing maternal mortality and also by professional training and work experience. Further, typical constraints on medical society involvement in policymaking were relaxed or removed, including those related to ESOG's organizational structure and history, and to political environment. Findings do not contradict theory positing medical society avoidance of socially conflictual health policymaking, but rather identify how the expected restrictions were less present in Ethiopia, facilitating medical society participation. Results can inform efforts to encourage medical society participation in policy reform to improve women's health elsewhere in sub-Saharan Africa.