Children with autism spectrum disorder (ASD) show atypical social behavior but vary in their social interaction style (SIS), ranging from social aloofness to awkward social approaches. In a 4-year follow-up study, we examined longitudinal stability and change of SIS in children and adolescents with ASD and a normal intellectual ability (n = 55; mean age Time 1: 13 years; mean age Time 2: 17 years). Children's SIS was assessed with a parent questionnaire, the Wing Subtypes Questionnaire. As expected, most participants (69%) showed SIS stability across the 4-year interval. Some participants (18%) shifted to a more typical or more active (but odd) SIS, while others (13%) shifted to a less typical or less active (but odd) SIS. A decrease in ASD symptoms predicted a shift toward a more typical or active SIS, but children's age and receptive verbal ability did not. SISs may be a meaningful way to create ASD subgroups and thus offer a promising research venue to further disentangle the heterogeneous autism spectrum. Autism Res 2019, 1-8. © 2019 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc. LAY SUMMARY: People with autism spectrum disorder (ASD) demonstrate different social interaction styles (SIS), ranging from social aloofness to awkward social approaches. We examined if and how SIS changes across a 4-year period in 55 children and adolescents with ASD (mean age Time 1 = 13 years; mean age Time 2 = 17 years). Most children (69%) showed the same SIS at both time points, indicating that SIS might be a relatively stable trait across adolescence.