Adults with chronic disease may experience uncertainty and depression when coping with their illness. This study identifies degrees of uncertainty and depression, as well as factors associated with depression in people with Parkinson's disease. The 120 participants included patients who visited the neurology outpatient department of a tertiary hospital in Seoul and individuals who attended public events managed by the Korean Parkinson's Disease Association. The mean age of the sample was 65.01 and 50.8% of patients were men. The mean scores of uncertainty and depression, measured using the Mishel Uncertainty in Illness Scale and Short Form Geriatric Depression Scale were 99.03 and 6.73, respectively. Approximately 68% of participants scored above the cut-off score for depression. Multiple regression analyses showed that uncertainty, perceived health status, and fatigue were factors significantly associated with depression. Nurses should be aware of and address these factors and their effects in order to implement interventions to prevent depression in people with Parkinson's disease.