: We assessed the influence of gait disorders (GD) on quality of life (QOL) in Parkinson's disease (PD). In a survey including the PDQ-39 and a new 8-item questionnaire of GD (8-QGD), 491 PD patients estimated their gait at the worst state, the effect of their GD on activities of daily living, compared the severity of GD with the other PD symptoms, evaluated the occurrence of freezing of gait (FOG), levodopa-resistant FOG, falls, activity limitation due to fear of falling (FOF), and the occurrence of injuries. Significant differences in PDQ-39 scores were found between three groups of patients divided with respect to the severity of GD. Linear multiple regression analysis showed that FOF had the highest impact on PDQ-39 scores (r=0.32, p<0.001). These results confirm that GD have a substantial impact upon the QOL in PD and suggest that FOF plays a major role in QOL deterioration.