Abdominal pain in children is a common, atypical symptom. The vast majority of abdominal pain is functional, non-life threatening and does not require extensive diagnostics. However, it should be remembered that the abdominal cavity is one of the most common locations of solid tumours in children. Carefully collected information and physical examination with oncological vigilance allow for the identification of alarming symptoms accompanying abdominal pain. These include: pain waking up from sleep, palpable mass in the abdominal cavity, vomiting, change in the rhythm of bowel movements, weight loss, fever, dysphagia, weakness, anaemia. The article presents a case report of a teenager with ovarian teratoma. It aims to illustrate the pitfalls and diagnostic difficulties associated with determining the causes of abdominal pain in children and adolescents. The discussion also summarises information on the epidemiology, aetiology and clinical symptoms of teratoma.