An analysis of modern medical literature carried out to study the main concomitant pathology in children with autism spectrum disorders gas revealed what concomitant diseases are more common in children with autism than in the general population. The structure of concomitant somatic pathology of children with autism includes disturbances from the gastrointestinal tract, sleep disturbances, the risk of overweight and obesity that affects the quality of life and complicates the manifestations of the main disease. The review of the current scientific literature has provided preliminary evidence that targeting the gut ecosystem has the potential to influence both autism spectrum disorders symptoms and gastrointestinal symptoms. The use of prebiotics and probiotics to correct behaviour and treat gastrointestinal diseases in children with autism has had limited effectiveness. The effectiveness and safety of using a gluten-free and casein-free diet in autism spectrum disorder is remaining controversial: a number of studies have reported no significant changes in autism symptoms, and the risk of developing nutrient deficiencies limits its clinical use. A combination of behavioural interventions and the use of the paediatric slow-release melatonin molecule are effective in the treatment of sleep disorders in children with autism. Conclusion. The high prevalence of concomitant somatic pathology in children with autism affects the course of the main disease, requiring a comprehensive examination of these children for its timely diagnosis and treatment. Taking into account the polyetiological nature of the etiopathogenetic mechanism of the development of autism spectrum disorder, the treatment of children with autism by a paediatrician should be carried out using evidence-based methods, with multidisciplinary support by specialists in the profile of existing concomitant disorders.