Non-alcoholic fatty liver disease (NAFLD) is becoming a common disease in both adults and children. Considering its multifactorial nature, a term “metabolically associated fatty liver disease” has been proposed, and new diagnostic criteria have been formulated to identify risk groups and to suspect the disease at early stages. Inflammatory bowel disease (IBD) is often associated with hepatobiliary manifestations. The prevalence of NAFLD among IBD patients is higher than in the general population, which is related to additional risk factors, such as history of previous intestinal surgery, long-term corticosteroid therapy, IBD severity and duration, parenteral nutrition, and sarcopenia. NAFLD can be combined with other liver pathologies, complicating them and worsening the course of IBD. NAFLD has an asymptomatic course and is often detected at late stages due to diagnostic difficulties. Clinical guidelines for the management of NAFLD in children with IBD have not been developed. The gold standard for diagnosis is liver biopsy with histological examination. Non-invasive methods of NAFLD diagnosis are being studied, including transient elastography and magnetic resonance imaging (MRI)-estimated proton density fat fraction (PDFF). In treatment, the first place is given to non-pharmacological methods: changing dietary habits, increasing physical activity. Data on pharmacological treatment methods are currently contradictory and continue to be studied. Key words: inflammatory bowel disease, non-alcoholic fatty liver disease, metabolically associated fatty liver disease