AIM: Millions of Ukrainian children have been internally displaced or fled to other countries because of the Russian war. This systematic review focused on their health needs and future challenges for clinicians. METHODS: A systematic literature search of the Medline, Embase and MedRxiv databases from 1 January 2010 to 31 March 2022 identified 1,628 papers on the health of Ukrainian children and 112 were relevant to this review. RESULTS: In 2019, under-5 mortality was 8 per 1000 live births in Ukraine. Underweight and adverse childhood experiences, including child abuse, were frequent compared to other European countries, while childhood obesity seemed less common. Alcohol consumption was common in women of reproductive age, including during pregnancy, risking foetal alcohol syndrome. Neonatal screening programmes provided low coverage. Vaccine hesitancy was common and vaccination rates were low. Other concerns were measles, HIV, antibiotic resistance and multi-resistant tuberculosis. Many children are expected to suffer from psychological and physical trauma due to the war. Other healthcare challenges include low COVID-19 vaccination rates and a preference for secondary and tertiary care, rather than primary care. Many people cannot afford medication. CONCLUSION: Ukrainian children often have poor health and host countries need to be aware of their needs.