Background:Single suture craniosynostosis (SSC) is a disorder, affecting brain growth. Reviewing literature reveals controversialists of papers in this field. Methods:This prospective study was conducted from 2014 to 2016. All the individuals, aged 2 to 16 years, whose medical records files were complete, with SSC from 1999 to 2013 were included. All patients had undergone cranial vault remodeling at Mofid Hospital, Tehran, Iran. Wechsler questionnaires, WPPSI-III and WISC-IV, were completed for each child based on his/her age. Results:Seventy children were included, with the mean age of 6.7 (±2.9) years. Forty-six (65.7%) children were boys while 24 (34.3%) were girls. Mean FSIQ for all of children was 95.5 (±13.2). Mean verbal IQ, performance IQ, verbal comprehension, perceptual reasoning, processing speed, and working memory are 93.4 (±14.1), 96.1 (±13.3), 97.5 (±13.9), 102.2 (±12.5), 94.5 (±9.8), and 97.5 (±12.9), respectively. There was statistically significant difference between FSIQ of children with SSC and that of unaffected children (P-value<0.05). There was significant difference between verbal IQ of children with SSC and that of unaffected ones (P-value< 0.007). There was significant difference between in processing speed between affected children and unaffected children (P-value<0.012). Conclusion: Children, aged 2 to 6 years, with SSC had a significantly lower Verbal IQ, and children, aged 6 to 16 years, with SSC had a significantly lower processing speed than their healthy counterparts. Though FSIQ of children with SSC falls within normal range, it is a little lower than healthy peers.