We examined data from 630 patients entered into the University of Kansas Medical Center's Parkinson's Disease (PD) Registry to determine if gender differences exist in terms of both cognitive and motor symptoms of PD. An analysis of the Mini-Mental State Examination scores indicated slightly higher scores for women relative to men. Although women had significantly better scores than did men on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS), they had a significantly greater prevalence of dyskinesias compared with men. These motor differences were significant only in patients with PD of greater than 5 years duration. There were no gender differences for age of diagnosis, Hoehn and Yahr Staging, Schwab and England Scale, or the mentation and activities of daily living sections of the UPDRS. We conclude that as PD progresses, gender differences emerge, with men exhibiting more severe parkinsonian motor features and women experiencing more levodopa-induced dyskinesia.