The methods of coping and their relationship to disease severity, cognitive function, depression and health-related quality of life (HRQoL) were examined in 79 Parkinson's disease (PD) patients and their carers. The coping methods of the PD patients were not associated with disease severity, cognitive function, or depression. In general the majority of correlations were weak. However, patients who used avoidance and cognitive coping methods reported improved HRQoL. Impaired cognitive function, poorer HRQoL and increased disease severity were associated with depression in patients. In carers, avoidance coping was associated with depression and cognitive impairment in the patient being cared for. These findings demonstrate the complex relationship in PD between impairment, quality of life, depression, cognitive function and the coping styles adopted by patients and carers. The study also highlights the difficulties in measuring these interactions with quantitative outcome measures.