Purpose: To examine patterns of sensory responsiveness (i.e., hyperresponsiveness, hyporesponsiveness, and sensory seeking) as factors that may account for variability in social-communicative symptoms of autism and variability in language, social, and communication skill development in children with autism or other developmental disabilities (DDs). Method: Children with autistic disorder (AD; n = 72, mean age = 52.3 months) and other DDs (n = 44, mean age = 48.1 months) participated in a protocol measuring sensory response patterns; social-communicative symptoms of autism; and language, social, and communication skills. Results: Hyporesponsiveness was positively associated with social-communicative symptom severity, with no significant group difference in the association. Hyperresponsiveness was not significantly associated with social-communicative symptom severity. A group difference emerged for sensory seeking and social-communicative symptom severity, with a positive association for the AD group only. For the 2 groups of children combined, hyporesponsiveness was negatively associated with language skills and social adaptive skills. Sensory seeking also was negatively associated with language skills. These associations did not differ between the 2 groups. Conclusions: Aberrant sensory processing may play an important role in the pathogenesis of autism and other DDs as well as in the rate of acquisition of language, social, and communication skills.