This article reports on the development and field trial of an integrated Head Start curriculum (Evidence-Based Program for Integrated Curricula [EPIC]) that focuses on comprehensive mathematics, language, and literacy skills. Seventy Head Start classrooms (N = 1,415 children) were randomly assigned to one of two curriculum programs: EPIC or the Developmental Learning Materials Early Childhood Express, with curricula implemented as stand-alone programs. EPIC included instruction in mathematics, language, literacy, and approaches to learning skills; formative assessment; and a learning community for teachers. Multilevel growth modeling through four direct assessments revealed significant main effects and growth rates in mathematics and listening comprehension favoring EPIC, controlling for demographics and special needs and language status. Both programs produced significant growth rates in literacy. (Contains 2 figures, 2 tables, and 2 notes.)