This paper investigates how the International Code of Marketing of Breast-milk Substitutes (the Code) was translated from an international policy framework to protect breastfeeding against inappropriate marketing practices into national level legislation, in the context of the advocacy efforts undertaken by Alive & Thrive with UNICEF and other partners. A real-time evaluation was carried out over 22 months in seven Southeast Asian countries, examining drivers of policy change and progress, and found that overall, countries made significant progress translating Code provisions into national measures. These drivers are described in this paper, which has the potential to help advocates effectively translate the Code into the legislature of other nations.