BackgroundIn recent decades some studies described the frequent co-occurrence of celiac disease autoimmunity and overt celiac disease in patients with autism. Therefore, it was suggested that celiac disease could play a possible role in the etiopathogenesis of autism spectrum disorder. However, several other studies have not confirmed this association. The aim of the present study was to elucidate the potential association between autism spectrum disorder and celiac disease.MethodsWe prospectively collected data from an Italian cohort of 223 children at the time of their clinical diagnosis of autism spectrum disorder in the 2019–2020 period. A serological celiac disease screening was performed and data were available for 196 patients; male (M):female (F) ratio = 4.4:1; median age = 3.6 years; age range = 1.6–12.8 years. Full-blown celiac disease was established according to the diagnostic algorithm of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) 2012 or 2019 guidelines. Fisher’s exact test was used to compare the celiac disease seroprevalence and prevalence in our autism spectrum disorder cohort and in the Italian healthy pediatric population studied by Gatti et al. to highlight the possible differences between the two groups.ResultsA not statistically significant difference between the celiac disease seroprevalence in our autism spectrum disorder cohort (4.08%) and Gatti’s Italian healthy group (2.22%) was found, p = 0.0810; OR = 1.871. A similar result emerged for overt celiac disease prevalences (2.24% versus 1.58%, respectively), p = 0.2862; OR = 1.431.ConclusionsOur data validates a weakness of association between autism spectrum disorder and celiac disease. On the basis of our results, a regular screening for CD in patients with ASD is not recommended to a greater extent than in the general population.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13052-023-01484-x.