Unusual responses to sensory stimuli have been described in autism spectrum disorder (ASD).The study examined the frequencies of "unusual sensory interests" and "negative sensory responses" and their relation to functioning in a large ASD population (n = 679). Having "unusual sensory interests" was reported in 70.4% and "negative sensory responses" in 66.0% of the ASD group. Having "unusual sensory interests" was associated with more severe reported and observed autism symptoms, lower cognitive ability and lower adaptive skills. In contrast, having "negative sensory responses" was only associated with more severe reported stereotyped behaviors. It is suggested that having "unusual sensory interests" is a part of a primary more severe type of ASD involving numerous developmental domains that might have a unique neurobiological origin.