The paper gives an overview of current diagnostic procedures in patients with clinical suspicion of hereditary fructose intolerance. On the basis of the literature and of a 9 years' experience at the Department of Paediatrics of the University of Graz a different approach according to the clinical condition of the patients is proposed (good clinical condition, severe liver disease, or bad clinical condition--i.e. liver biopsy is ethically not justified). The aim of this approach is to minimize invasive procedures for the children.