Autistic spectrum disorder is a neurodevelopmental disorder characterized by qualitative impairment in social interactions and communication skills. In addition to these core features, sensory processing abnormalities such as auditory hypersensitivity have been frequently reported. Although the cause of auditory hypersensitivity remains unknown, it is thought to be associated with decreased inhibitory processing, possibly resulting from an abnormal sensory gating system or dysfunction of inhibitory interneurons. Its relation to drugs has not been well documented to date. In the literature, there is only one case on hyperacusis that worsened with risperidone in a 5-year-old girl with autism. Here we represent the case of an 11-year-old boy with autism, in whom hyperacusis worsened with risperidone, decreased after the discontinuation of the medication, and re-occurred after the prescription of the drug again. Although auditory hypersensitivity tends to affect the child's daily life negatively and is found to be correlated with behavioral problems in autistic patients, we still know very little about its etiology, treatment, and conditions related to it. There is a great need for conducting further studies in this regard.