BackgroundBoth autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) are early neurodevelopmental disorders that present notable diagnostic problems and share clinical features. The current research intends to clarify the sensory profile, visual-evoked potential (VEP), and auditory-evoked potential of children diagnosed with autism spectrum disorder (ASD), ADHD, and typically developing children (TD). We have observed sensory processing problems in 42–88% of children diagnosed with autism and approximately 50% of children diagnosed with ADHD.ResultsThe parents of 37 children diagnosed with ASD, 41 children diagnosed with ADHD, and 43 children who were typically developing completed the short sensory profile (SSP) along with standardized questionnaires used to assess the symptoms and autistic behaviors. We assessed intellectual functioning and evoked potential in all the groups. There were more sensory problems in the ASD and ADHD groups than in the control group (P < 0.001); however, autism and ADHD differed in all subscales except unresponsiveness, auditory filtering, and visual/auditory subscales. Also, the ASD group and ADHD group showed a more significant delay in visual-evoked potential VEP than the control group (mean and SD of right eye p100 latency 150.85 ± 48.70 in ASD vs 119.28 ± 18.06 in ADHD vs 103.42 ± 5.19 in typically developing group, left p100 latency 141.09 in ASD ± 32.55 vs 116.51 ± 10.1 in ADHD vs 103.0 ± 5.91 typically developing group). Additionally, the ASD group significantly deviated from norms in the absolute latency of waves I, III, and V, as well as the inter-wave intervals of I–III and III–V in the auditory-evoked potential. Furthermore, there was a statistically significant distinction between the ADHD and the TD groups in terms of left wave III and V latency and left interpeak latency between I–III and III–V.ConclusionChildren diagnosed with ASD and ADHD have a greater likelihood than typically developing children to experience sensory processing abnormalities; as a result, we recommend basic assessment, follow-up, and designing the most appropriate intervention.