This study was designed to demonstrate the effect of implementing multi-component vocabulary strategy instruction in fourth grade social studies. Curriculum was designed for a six-week period and was intended to actively engage students and reinforce retention of word meanings in isolation and in context. Teachers were randomly chosen for assignment to the intervention and/or to the comparison group. The study included 375 fourth-grade students from 3 different districts and 5 schools. The student population consisted of 29 classes taught by 23 different teachers. Two different vocabulary and comprehension measures were administered, and results were analyzed using difference score analyses and repeated measures ANOVAs. Outcomes were consistent across both administered measures. Although student scores improved in both the group receiving the intervention and the group receiving regular classroom instruction, findings indicated that the group receiving the intervention showed greater gains and persisted longer than in the comparison classrooms.