Purpose: This study was conducted to determine whether a narrative intervention program that targeted the use of mental state and causal language resulted in positive gains in narrative production for children with autism spectrum disorder (ASD). Method: Five children (2 girls and 3 boys) who had been diagnosed with ASD participated in the study. Children ranged in age from 8 to 12 years and were recruited through an autism clinic. Intervention was provided for two 50-min individual sessions per week for a total of 21–33 sessions (depending on the student). Children’s spontaneous stories, collected weekly, were analyzed for overall story complexity, story structure, and the use of mental state and causal language. Following a multiple-baseline across-participants design, data were collected for lagged baseline and intervention phases over a 6-month period. Results: All of the children made gains on all 3 measures of narration after participating in the instruction, with clear changes in level for all 5 children and changes in trend for 4 of the 5 children. The gains were maintained after intervention was discontinued. Conclusion: The results demonstrate the efficacy of the 3-phase narrative instruction program for improving the fictional narration abilities of children with ASD.