This study examined the effects of Interactive Writing, a dynamic approach to writing instruction designed specifically for young children, on the independent writing of first graders enrolled in urban schools in a large metropolitan area. Children in the Interactive Writing condition (N = 49) showed greater growth on measures of independent writing than a comparison group (N = 52). Students' written performance in response to a prompt indicated that those who participated in Interactive Writing not only improved in their overall independent writing, but also made greater gains on nine out of 10 of the individual subcomponents of writing measured: Ideas, Organization, Word Choice, Sentence Fluency, Spelling of High-Frequency Words, Spelling of Other Words, Capitalization, Punctuation, and Handwriting. These results were obtained in classrooms that spent an average of 10.5 minutes a day engaged in Interactive Writing and thus demonstrate its potential as a daily practice to improve children's independent writing. (Contains 2 figures and 4 tables.)