Nutritional status was assessed in a group of patients with Parkinson's disease. Weight loss since the onset of disease occurred in 52% of the patients and 22% had lost more than 12.8 kg. Although 67% of patients experienced eating difficulties of some kind, dietary intakes of protein and energy were not significantly lower than recommended intakes. Plasma levels of albumin (44.2 g/l vs 45.7 g/l), vitamin A (2.61 vs 2.94 mumol/l), vitamin E (22.0 vs 32.0 mumol/l), iron (15.3 vs 18.3 mumol/l) and zinc (14.2 vs 18.7 mumol/l) were significantly lower (P < 0.05) in the patients than in healthy controls. Levels of ferritin, total iron-binding capacity and copper were similar between groups. The potential significance of low levels of vitamin E and zinc are discussed in relation to oxidative stress in the pathogenesis of this disease.