Tardive dyskinesia (TD) remains a significant problem for patients and physicians. Several reports have suggested that vitamin B6 (pyridoxine) can be helpful in the treatment of some neuroleptic-induced movement disorders, including parkinsonism and TD. This report presents the results of a preliminary study of five patients with TD who underwent a four week open-label clinical trial of vitamin B6 (100 mg/d) in addition to their regular medications. The severity of the involuntary movements was assessed using the Abnormal Involuntary Movement Scale (AIMS), Barnes Akathisia Rating Scale (BARS) and the Simpson-Angus Scale (SAS). The patients' clinical status was assessed with the Brief Psychiatric Rating Scale (BPRS). With the addition of vitamin B6 to their treatment, four patients had clinically significant (greater than 30%) improvement on the measures of involuntary movement and, in three cases, there was also clinically significant improvement on the BPRS. None of the patients had side effects attributable to vitamin B6. The results suggest that vitamin B6 may alleviate TD, but it will need to be further tested in controlled double-blind trials.