The frequency of taste disorders in idiopathic facial palsy (IFP) and B. burgdorferi-associated facial palsy (BFP) was retrospectively assessed in a cohort of patients with acute peripheral facial palsy (AFP). A significant (>10/microl) CSF pleocytosis was found in 17% of the patients who underwent lumbar puncture for AFP. In two centres, 26 patients with BFP were identified by CSF and serological criteria. The control group (patients with IFP) consisted of 59 patients from one of the centres in whom BFP was excluded by CSF examination. AFP patients of both centres are routinely questioned about taste disorders according to the hospitals' standards. A taste disorder was found in 46% of the IFP and 31% of the BFP cases (not significant). About one-third of the BFP patients complained of radicular or back pain. We conclude that a history of taste disorder is not helpful in distinguishing clinically between BFP and IFP.