Bladder dysfunction may cause disabling symptoms in Parkinson's disease (PD) patients. The majority patients' experience symptoms as urinary urgency and nocturia suggest overactive bladder. This seems to be due to an altered brain–bladder relationship because of alteration in fronto-basal ganglia D1-dopaminergic circuit that normally suppresses micturition-reflex. Previous studies demonstrated beneficial effect of D1/D2 dopamine-receptors chronic-stimulation on detrusor overactivity of PD-patients.The present study was aimed to evaluate possible effect of extended-release (ER) Levodopa administered at bed-time on both nocturia and nocturia-related quality-of-life (NQoL) in PD-patients. 106 PD-patients (Hoehn and Yahr>1 and < 4, mean age 66 years, 59 females and 47 males) were enrolled by 7 Movement Disorders out-patients clinics. Patients undergo to International Prostatic Symptoms Scale-IPSS, including 1-item about nocturia (item 7), and to Nocturia Quality of Life-NQoL questionnaire, at baseline and after two-months of Extended-Release L-dopa (L-dopa/carbidopa or L-dopa benserazide) treatment at bed-time. Statistical analysis showed significant improvement on both total IPSS, item 7and NQoL scores following two-months ER L-dopa-treatment. ΔIPSS score inversely correlated with disease duration. This results support previous evidence of pathophysiological involvement of dopaminergic transmission on bladder dysfunction in PD. •Overactive bladder is the most common symptoms in PD patients.•Overactive bladder depends on altered D1dopaminergic circuit.•Extended-release L-dopa administration improves bladder dysfunction in PD patients.