This article reports on 2 studies with kindergarten and first-grade children from a low-achieving elementary school that provided vocabulary instruction by the students' regular classroom teacher of sophisticated words (advanced vocabulary words) from children's trade books that are typically read aloud. Study 1 compared the number of sophisticated words learned between 52 children who were directly taught the words and 46 children who received no instruction. As expected, children in the experimental group learned significantly more words. Study 2, a within-subject design, examined 76 children's learning of words under 2 different amounts of instruction, either 3 days or 6 days. In Study 2, the vocabulary gains in kindergarten and first-grade children for words that received more instruction were twice as large. Student vocabulary was assessed by a picture test where students were presented with pictures that represented different words and were asked to identify which picture represented the word that the tester provided. The verbal test was similar but used a sentence description of a scenario instead of a picture. The instructional implications for which words to teach and how to teach them to young children are discussed.