We examined recalled narratives of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD; N = 28) and without ASD (FXS-O; N = 29), and compared them to those of boys with Down syndrome (N = 33) and typically developing (TD) boys (N = 39). Narratives were scored for mentions of macrostructural story grammar elements (introduction, relationship, initiating events, internal response, attempts/actions, and ending). We found that narrative recall is predicted by short-term memory and nonverbal mental age levels in almost all groups (except TD), but not by expressive syntax or caregiver education. After adjusting for these covariates, there were no differences between the three groups with intellectual disability. The FXS-ASD group, however, had significantly poorer performance than the TD group on the overall story grammar score, and both the FXS-O and FXS-ASD groups had lower attempts/actions scores than the TD group. We conclude that some form of narrative impairment may be associated with FXS, that this impairment may be shared by other forms of intellectual disability, and that the presence of ASD has a significantly detrimental effect on narrative recall.