This investigation examined the use of computer-assisted instruction (i.e., "WordMaker") on students having different levels of reading ability. Of particular interest were the effects of "WordMaker" on the spelling performance of first graders in a co-taught classroom. In a short 10-week period, the "WordMaker" software program had a positive impact on children's decoding and spelling skills. Eighty-three percent of the students experienced gains between the pre- and posttest scores. Findings suggest that "WordMaker" is an effective complement to other activities associated with the first grade curriculum (e.g., spelling and decoding) and has the potential to enhance students' reading and writing skills. (Contains 2 tables and 3 figures.)