Although several decades of research has highlighted the contribution of classroom behaviors to students' mathematics and reading performance, this relation with regard to writing performance has been examined to a lesser extent. Therefore, this study sought to examine a wide range of classroom behaviors as predictors of written expression, spelling, and handwriting performance across male and female students. Data were collected from 80 third-grade students and their teachers (n = 4). Results indicated that for female students, high levels of accuracy and consistency of academic work were related to greater written expression performance. This pattern of findings was also observed for spelling performance, regardless of gender. A relation was not observed between classroom behaviors and handwriting performance. This study provides preliminary findings that suggests the importance of considering the contribution of classroom behaviors to students' writing performance.