Background: Verbal Fluency is reduced in patients with Parkinson’s disease, particularly if treated with deep brain stimulation. This deficit could arise from general factors, such as reduced working speed or from dysfunctions in specific lexical domains. Objective: To test whether DBS-associated Verbal Fluency deficits are accompanied by changed dynamics of word processing. Methods: 21 Parkinson’s disease patients with and 26 without deep brain stimulation of the subthalamic nucleus as well as 19 healthy controls participated in the study. They engaged in Verbal Fluency and (primed) Lexical Decision Tasks, testing phonemic and semantic word production and processing time. Most patients performed the experiments twice, ON and OFF stimulation or, respectively, dopaminergic drugs. Results: Patients generally produced abnormally few words in the Verbal Fluency Task. This deficit was more severe in patients with deep brain stimulation who additionally showed prolonged response latencies i)