Preschoolers' (N = 156) classroom language and literacy experiences, defined across multiple dimensions, and their vocabulary and emergent literacy development were investigated. Videotaped classroom observations revealed substantial variability in amount and types of language and emergent literacy activities, across classrooms and for individual children within classrooms. Generally, more time in emergent code-focused activities was associated with preschoolers' alphabet and letter-word recognition growth, whereas more time in meaning-focused activities (e.g., book reading) was related to vocabulary growth. Only teacher- and teacher-child-managed activities were associated with alphabet and letter-word growth, whereas child-managed experiences, including play, were also associated with vocabulary growth. Overall, the effect size for student-level, code-focused instruction (small group) was about 10 times greater than was its classroom-level (whole-class) counterpart. There were Child x Instruction interactions, with the impact of different activities varying with preschoolers' incoming vocabulary and emergent literacy.