This study compares the effectiveness of context clue strategy instruction to wide reading practices in terms of their impact on the vocabulary knowledge of students who read at frustration level. The participants were 44 sixth-grade students from a middle grades school. Students were randomly assigned to experimental and control conditions. The experimental condition students were trained to use context clues to infer meaning from context using a direct instruction method. A contextual vocabulary test consisting of 30 multiple-choice items was used to assess the students' understanding of the word meanings in context. The results indicated that the experimental condition demonstrated higher levels of improvement in the vocabulary knowledge than the control condition (which practiced a wide reading strategy. The findings suggest that a reading intervention focused on using context clues can have a worthwhile effect on the ways in which students who experience difficulties with comprehension increase their proficiency in learning from context and hence build their vocabularies.