Aripiprazole is a novel antipsychotic medication characterized by partial agonism at the D2 and 5-HT1A receptors and by antagonism at the 5-HT2A receptor. The aim of the present study was to evaluate, in an open-label pilot study, the effects and safety of very small doses of aripiprazole on l-dopa-induced dyskinesia of a group of PD patients who did not show a significant clinical benefit by pharmacological treatment with amantadine and mirtazapine. Twelve PD patients with peak-dose LID were enrolled in a period of 1 year. Aripiprazole dosage was of 0.625 mg/day. The ten patients who continued taking aripiprazole displayed a significant decrease in the intensity and frequency of dyskinesias in all parts of the body, particularly in trunk movements (AIMS score T0 = 14.1 ± 3.6 vs. final score 2.4. ± 2.6; P = 0.005). Our study suggests that aripiprazole at very low doses is tolerated and could be efficacy in treating LID.