The ability to write informatively is a skill not only required by the U.S. Common Core State Standards but is also essential for preparing students to be successful in college. The purpose of this exploratory study was to evaluate the effects of a self-regulated strategy development (SRSD) informative writing intervention for high school students with and at-risk for learning disabilities. Using a pretest--posttest design, 18 high school students received instruction on identifying credible source texts; reading and annotating source texts; and planning, writing, and revising informative essays that incorporated central ideas and details from source texts. Student essays were scored for overall quality, number of genre elements, transitions, total words written, and central ideas and details from the sources. Students made statistically significant gains in their informative genre knowledge and writing skills in all measured outcomes. Students also reported increased self-efficacy and found the intervention to have acceptable social validity.