Gaze avoidance and perseverative language impact pragmatics in autism spectrum disorder (ASD) and fragile X syndrome (FXS). We examined these features during conversation samples in boys with ASD ( n=10) and boys with FXS and ASD (FXS+ASD; n=10). Both groups had similar high rates of gaze avoidance and topic and conversation device perseverations, yet these features were not correlated with one another. Boys with FXS+ASD produced a higher proportion of single utterance perseverations. Results from this study highlight the need for future research to identify potential mechanisms influencing the presence of language perseverations and gaze avoidance.