This study investigated relationships between teacher talk exposure in preschool and school and children's second language vocabulary acquisition. Teacher talk exposure and vocabulary acquisition in Turkish-speaking children learning Norwegian and attending various classrooms were assessed yearly from when the children were in their next-to-last year of preschool attendance until 1st grade. Teacher talk lexical input was identified as amount (density of word tokens), diversity (density of word types), and complexity (density of word types appearing within explanatory talk) of input, based on videotaped teacher-student interactions. Children's vocabulary skills in Turkish and Norwegian were assessed using translated versions of the Peabody Picture Vocabulary Test and the Word Definition Subscale of Reynell Developmental Language Scale. Only a few relationships were found between the amount, diversity, and complexity of teacher talk and the target children's immediate second language vocabulary skills. The amount, diversity, and complexity of teacher talk in preschool did, however, predict subsequent second language vocabulary skills in 1st grade. Controlling for maternal education and age of preschool entrance, teacher talk lexical input in preschool predicted variance in both 1st-grade receptive vocabulary and word definition skills. (Contains 7 tables and 4 notes.)