This case study examined how a kindergarten teacher used and adapted three sets of science curricular materials to promote vocabulary development. Analysis of 126 minutes of science instruction across three video-recorded lessons and the curricular materials used focused on target word selection, discussion questions, and use of educative features. Findings indicate that high-quality materials provided conceptually coherent target words that were relevant to science standards and discussion prompts that were also relevant to standards and related to target words. The teacher largely adopted these target words and discussion prompts in her enacted lesson. Less supportive materials resulted in less coherent and relevant word selection and required the teacher to add her own discussion questions. The teacher showed some uptake of reminder callouts highlighting opportunities to promote word learning alongside sensemaking. This study highlights the critical role of high-quality curricular materials in integrating vocabulary and science learning in early-elementary classrooms.