The purpose of this article is to describe the RotaTeq Nicaragua Partnership and the evaluation of the public health impact of the vaccine conducted by the partners, including the creation of a rotavirus surveillance program and a vaccine effectiveness assessment. The three main objectives of the partnership were to demonstrate that a new rotavirus vaccine could (1) be introduced rapidly in a developing country, (2) be successfully integrated into the existing vaccine delivery infrastructure and (3) have a significant and measurable public health impact at the end of the 3-y program. The vaccine impact assessment required collaboration among partners with different areas of expertise, including the Nicaraguan Ministry of Health, Merck, local hospitals, government health clinics, laboratories, and a Technical Advisory Group. Through the partnership, RotaTeq became available in a GAVI-eligible developing country, Nicaragua, in the same year it was approved in the US. Vaccine coverage rapidly reached over > 90% of eligible Nicaraguan children. The impact assessment evaluated over 10,000 subjects and leveraged and enhanced the existing diarrheal surveillance infrastructure, ultimately providing the scientific community with some of the first real-world rotavirus vaccine effectiveness data from a developing country. The successful public-private partnership (PPP) was internationally recognized as a model for the rapid adoption of a new vaccine in a developing world setting. The model could be adapted to benefit other PPPs interested in demonstrating the impact of their own programs.