This single subject study concerned how a 13 year-old student with specific learning disabilities used metacognition as he composed discourse in response to a writing prompt. Ethnographic procedures were used to collect and analyze data. The participant engaged in a think aloud procedure as he composed a paper about a famous historical figure. His transcribed verbalizations were analyzed by use of domain and taxonomic analysis for use of metacognitive strategies. Results indicated that the participant organized and controlled the writing process by using the following four domains of metacognitive strategies: (a) planning discourse/thinking, (b) evaluating discourse/thinking, (c) recognizing problems with discourse/thinking, and (d) repairing discourse/thinking. The participant engaged in knowledge-telling behavior and focused on surface level text structure to produce a final product at a low abstractive level. Small sample size prevents generalizations, but other research suggests that particular metacognitive strategies can be taught to support more successful writing.