Objective To determine if side and type of initial motor symptoms in Parkinson disease predict risk for later development of cognitive impairment or depressive symptoms. Methods We recruited 124 nondemented patients with Parkinson disease to participate in a cohort study of cognitive function and depressive symptoms that used validated neuropsychological tests and a depressive symptom inventory. We first reviewed the patients’ charts to determine their initial motor symptom and side of onset, and then classified the patients into 4 groups: right-side onset tremor, right-side onset bradykinesia/rigidity, left-side onset tremor, and left-side onset bradykinesia/rigidity. We excluded patients with bilateral symptom onset. We used analysis of variance on neuropsychological test performance and depressive symptoms to determine if group classification affected risk of cognitive impairment or depressive symptoms. We controlled our analyses for disease duration and motor severity as measured by the Unified Parkinson Disease Rating Scale Part III motor score. Results There were no differences in any cognitive measure by side and type of initial motor symptoms. The right-side onset tremor group had the lowest depressive symptom scores, and no patient in any group reported severe depressive symptoms. Conclusion Our findings suggest that patterns of nigral cell loss correlating to the initial side and type of motor symptoms in Parkinson disease are not related to the risk of later cognitive impairment. By contrast, patients with right-side onset of tremor appear to have a lower risk of depressive symptoms than patients with other presentations.