We studied striatal dopamine D1 and D2 receptors in patients with juvenile neuronal ceroid lipofuscinosis (JNCL) with positron emission tomography (PET) using a dopamine D1 receptor antagonist [11C]NNC 756 and a dopamine D2 receptor antagonist [11C]raclopride as ligands. The mean [11C]NNC 756 uptake value in JNCL was reduced by 15 % from the mean control value in the putamen (p < 0.01) and by 13 % in the caudate nucleus (p < 0.01). The mean [11C]raclopride uptake in JNCL patients was not significantly different from the mean of the control group either in the putamen or the caudate nucleus. Our results show a mild reduction in striatal dopamine D1 but not in D2 receptors in JNCL, indicating slightly impaired striatal neuronal function. The contribution of these changes to the extrapyramidal symptoms of the patients and their treatment deserves further studies.