Effective curricula are considered to be the cornerstone of successful programming in Extension. However, there is no universal operationalized definition of the term "curriculum" as it applies to Extension. Additionally, the development of curricula requires a systematic process that takes into account numerous factors. We provide an operational definition of "curriculum" by describing the parts of a curriculum, discussing the organization of those elements, and recommending theoretical frameworks that complement the learn-by-doing approach used in Extension. We also describe strategies to guide curriculum development, adaptation, and evaluation that will help advance the potential of Extension curricula to achieve their intended outcomes. [Additional support in the preparation of this article was provided by Ramona Carlos, Haylie Canfield, and Taylor Gullikson.]