A study investigated the effects of preteaching vocabulary on students' performance of a writing task targeted to the use of those words. Subjects were 50 fourth grade and 55 sixth grade students. Materials included a pretest narrative writing assignment, a 10-word vocabulary pretest and posttest, a vocabulary instructional booklet with teacher's guide, a posttest narrative writing assignment, and an attitude inventory. The experimental treatment consisted of activities designed to teach a set of 10 words related to the topic of the posttest writing assignment. The results of the writing assignment indicated that the fourth grade students receiving the vocabulary instruction used an average of 80% of the new words in their narratives, while the sixth grade students receiving instruction used an average of only about 40% of the words. However, the fourth grade students did not always use the words correctly, whereas the sixth graders showed a more tentative but more correct use of the words. On the vocabulary tests, both the fourth and the sixth grade experimental students learned the words taught. The results of the attitude inventory indicated that the instructional unit was well received. The majority of students both enjoyed the unit's activities and attempted to use the new vocabulary in their subsequent writing. The overall quality of the experimental students' writing also improved. (Testing materials, an outline of the instructional unit, and the scoring scale are appended.) (HTH)