This article provides a field-based account of how to develop and implement an adult workplace literacy program for English as a Second Language (ESL) students based upon the principles of a social practices definition of literacy. The purpose of the program is to provide basic literacy instruction for the growing population of Spanish-speaking apprentice carpenters in northern Nevada. The following parties participated in the development of the program (Pseudonyms are used in place of actual names.): a college professor of English as a second language and his graduate students at the University of Nevada, Reno (UNR); the Joint Apprentice Training Committee (JATC), a union school of carpentry in northern Nevada; Spanish-speaking apprentice carpenters attending the JATC; and representatives of various construction companies. This article details the development of a curriculum for the UNR/JATC workplace ESL literacy program, with a particular emphasis on the role that the socio-cultural definition of literacy played in the development of the curriculum. After a discussion of the context for the UNR/JATC workplace ESL literacy program, the authors detail the steps taken in developing the curriculum. (Contains 4 tables.)