This study compared the writing motivation of students with language impairments (LI) and their typically developing (TD) peers. For the study 272 students (33 students with language impairments, 242 TD peers) aged 8-10 years, in 11 elementary schools, were sampled. The two groups completed self-report measures of writing motivation and 20 grade-appropriate spelling words from a standardized measure. Multiple regression analyses were used to examine the hypothesis that perceived writing competence--a self-evaluative judgment of writing competence--mediates the relationship between LI status (LI or TD) and intrinsic forms of writing motivation. Statistical analyses indicated that (1) students with specific language impairments reported lower levels of perceived writing competence and intrinsic writing motivation; (2) LI status was a significant predictor of perceived competence after spelling, grade and gender were controlled; and (3) when spelling, grade and gender were controlled, perceived writing competence was a significant predictor of intrinsic writing motivation, but LI status was not. Future research is necessary to further describe external influences on the writing motivation of students with LI and appropriate motivational supports. (Contains 8 tables and 2 figures.)