Policy-makers, administrators, researchers, and teachers are increasingly vested in ensuring the quality of preschool instruction, particularly in the areas of language and literacy. This research was conducted to characterize the quality of language and literacy instruction in 135 publicly funded preschool classrooms serving at-risk pupils. As all teachers in these classrooms were implementing the same language and literacy curriculum, we also studied the interrelationships among procedural fidelity to a prescribed curriculum and the quality of language and literacy instruction, determining whether procedural fidelity is associated or disassociated with quality instruction. Results showed that the quality of language and literacy instruction in classrooms was low, with few teachers delivering high-quality instruction. Although teachers were able to implement a prescribed language and literacy curriculum with a high degree of procedural fidelity, this was not associated with quality instruction. Few structural characteristics of classrooms or teachers were systematically associated with quality of instruction. Findings have important implications for professional development of teachers by suggesting a need for a sustained and coherent focus on the process of instruction to elevate instructional quality in language and literacy.