The psychometric properties of a scale assessing the writing self-efficacy of 1,258 students from Grades 4 to 11 were analyzed with exploratory factor analysis. Two factors emerged, 1 designating basic grammar skills and 1 designating more advanced composition skills. The Writing Self-Efficacy Scale (F. Pajares & G. Valiante, 1999) functioned equally well at each academic level assessed. (Contains 3 tables.)