This study examined the effects of explicit instruction using semantic maps on cross-curricular vocabulary in a second-grade classroom. The researcher taught vocabulary words from various subject areas to 21 students using explicit instruction methods like child-friendly definitions and examples, followed by having students complete semantic maps in pairs. Data was collected through pre- and post-tests of general vocabulary and target words, as well as daily and bi-weekly assessments during the 8-week intervention. Results showed significant gains in students' expressive vocabulary, receptive vocabulary, and knowledge of target words from pre- to post-testing. During the intervention, students' understanding of weekly vocabulary words improved. Boys showed slightly greater gains in expressive vocabulary than girls. The study suggests