Juvenile neuronal ceroid lipofuscinosis (JNCL) is one of the most common neurodegenerative disorders in childhood and adolescence. The clinical picture includes diverse and complex psychiatric symptoms that are difficult to treat. Only symptomatic treatment is available. To improve symptomatic therapy, it is important to recognize the symptoms. The purpose of this study was to identify predominant psychiatric symptoms in patients with JNCL. The study included 27 patients with JNCL with and without psychotropic treatment. The mean age was 15.2 (range 9-21) years. Characteristic psychiatric symptoms in this patient group were clarified by using the following standardized questionnaires filled in by parents, teachers and the patients themselves: Child Behavior Checklist (CBCL), Teacher Report Form (TRF) and Children's Depression Inventory (CDI). The symptoms were recorded for the entire study group and compared between patients with and without psychotropic treatment and between genders. The patients had a large number of psychiatric symptoms according to the CBCL and TRF. The most commonly reported symptoms were social, thought, attention problems, somatic complaints and aggressive behaviour. Patients receiving psychotropic medication had more psychiatric symptoms according to the CBCL and TRF. Moreover, female patients had more problems than male patients according to the CBCL. The total psychiatric symptom score was at clinical or borderline range for psychiatric disturbance in 74% of patients. The number of depressive symptoms reported by the patients themselves was low. JNCL patients suffer from a multitude of psychiatric symptoms. To improve drug choice and dosage, a thorough evaluation of these symptoms by standardized methods is needed before initiating treatment. Progress and possible adverse effects of treatment should be monitored on a regular basis.