Choline levels in lumbar cerebrospinal fluid (CSF) were measured in patients with craniocerebral trauma (N = 67), Parkinson's disease (N = 20), miscellaneous extrapyramidal disorders (N = 28) and Huntington's chorea (N = 5). No differences in CSF choline levels were observed between these diagnostic groups and a group of neurological controls (N = 22). However, CSF choline levels were found to increase with age.