The aim of the present work was to study the characteristics of motor complications in a group of familial Parkinson's disease (fPD) patients in comparison with matched sporadic PD (sPD) patients. Fifty-one fPD and 51 sPD patients matched for age and disease duration, used as controls, were included in the study. The Unified Parkinson's Disease Rating Scale was completed during clinical examination and all patients were questioned about the characteristics of motor complications. The mean time from start of L-dopa therapy to the onset of motor fluctuations (MF) and L-dopa-induced dyskinesias (LID) as well as the mean time from symptom onset to the development of MF and LID was significantly shorter in the fPD group of patients. An analysis revealed a higher occurrence of MF and LID in fPD patients in the group with disease duration of 5 years or less. FPD may be associated with a higher prevalence and earlier onset of motor complications during the initial stages of the disease. Genetic factors may contribute to the specific characteristics of motor complications in fPD.