We ascertained the prevalence of apraxia of eyelid opening (AEO) in a community located in Puglia, a region of southern Italy. The crude prevalence rate was 59 per million (95% confidence interval, 24-173). AEO coexisted with adult onset blepharospasm in 75% of cases, with atypical parkinsonism in 25% of cases. Among the overall patient population seen at our movement disorders clinic from 1987 to 1997, AEO was isolated in 10 otherwise healthy individuals, associated with adult-onset dystonia in 13 cases, and associated with a parkinsonian syndrome in 9 cases. The frequency of AEO was 10.8% in the dystonia group, and 2.1% in the overall parkinsonian group (Parkinson's disease, 0.7%; progressive supranuclear palsy, 33.3%). In two patients with possible progressive supranuclear palsy, AEO worsened after increasing levodopa dosage or acute apomorphine challenge and disappeared following levodopa discontinuation. AEO developing in the setting of a parkinsonian syndrome may be either disease- or drug-related.