Convergent research suggests that people with ASD have difficulties localizing sounds in space. These difficulties have implications for communication, the development of social behavior, and quality of life. Recently, a theory has emerged which treats perceptual symptoms in ASD as the product of impairments in implicit Bayesian inference; as suboptimalities in the integration of sensory evidence with prior perceptual knowledge. We present the results of an experiment that applies this new theory to understanding difficulties in auditory localization, and we find that adults with ASD integrate prior information less optimally when making perceptual judgments about the spatial sources of sounds. We discuss these results in terms of their implications for formal models of symptoms in ASD.