In this single-case design study we examined the effects of a summarizing strategy on the written summaries of students with learning disabilities (LD). Three students with LD in fifth and sixth grades learned a mnemonic-based strategy (WINDOW) for writing summaries taught using the self-regulated strategy development (SRSD) approach. Visual analyses were conducted, along with estimated effect sizes using quantitative methods at both the individual level and across cases. Results indicate that the treatment program had a positive effect on the quality of written summaries. Anecdotal evidence suggested that the students understood the strategy and could independently recall the steps of the strategy by the end of the intervention. Results suggest that the strategy has the potential to improve the summary writing skills of students with LD. Limitations and future directions are discussed.