Forty patients with Parkinson's disease were compared with 33 normal controls with respect to their performance in the Wechsler Adult Intelligence Scale subtests "information", "similarities", "block design", and "picture completion", in a test for visual neglect (Hamsher's line cancellation test) and in tests for visuospatial and visuorotational abilities (cube task from Amthauer's intelligence structure test and Rybakoff figure test, as revised by Meili). The findings show that the patients scored significantly worse than the controls (Mann-Whitney U test, P = 0.004) in the Rybakoff figure test, testing visual concept finding, imagination and visual rotation. In the other tests no significant differences were found between the patients and the controls. The deficit of the patients in the figure test of Rybakoff correlated significantly with tremor (P = 0.013), akinesia (P = 0.009), disability (P = 0.043), and age (P = 0.004, Spearman rank correlation).