Purpose: This study focused on factors that contributed to writing quality in adults who were pursuing a General Educational Development (GED) diploma through an adult basic education program and university students who were pursuing a college degree. We explored the role of transcription (handwriting and spelling), working memory, oral language, and discourse knowledge in the writing process and the extent to which each component contributed to the writing quality of adults. Method: This descriptive study examined the relationship between cognitive skills and writing quality among students enrolled in an Adult Basic Education (ABE) program compared to undergraduate university students in the Southeastern United States. A hierarchical regression analysis was used to explore cognitive predictors of writing quality in these students. Participating students (N=49) provided two writing samples (i.e. narrative and expository) from the Test of Written Language and the Wechsler Individual Achievement Test-III. Each passage was scored using holistic quality rating scales from the standardized tests. Students were also assessed using standardized measures of oral language, working memory, transcription, and an experimental measure of discourse knowledge. Results: Results indicated that a significant amount of variance was explained by the cognitive and mechanics predictors included in our model. Furthermore, measures of phonological awareness, spelling, and handwriting accounted for unique variance in writing quality in both students in the ABE program and undergraduate students. Conclusions: Results from this study suggested that there were important cognitive and mechanical skills related to writing quality in adults. These results were consistent with other studies of predictors in children and predictors of other literacy outcomes in students in ABE programs. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]