Introduction Chylomicron retention disease is a rare type of familial hypocholesterolemia (approximately 40 cases described worldwide), characterised by malnutrition, growth failure, vitamin E deficiency and hepatic, neurologic and ophtalmologic complications. Diagnosis is often delayed because symptoms are nonspecific and hypocholesterolemia may be attributed to malnutrition secondary to chronic diarrhoea.

Materials and methods We present the case of a 11 years old patient who met all the diagnostic criteria, including serum cholesterol level consistently lower than 100 mg/dl. The abnormal lipid profile established the diagnosis, after which after which treatment was initiated by low fat diet and high doses of fat soluble vitamins.

Results The patient was very compliant and followed the recommendations very strictly. Accordingly, hepatic steathosis decreased, but unfortunately the neurologic and ophatlomogic problems persisted.

Conclusion While this rare disease is easily diagnosed, it is important that the diagnosis is rapidly established in order to avoid neurologic and ophthalmologic long term complications.