We undertook a randomized, double-blind, placebo-controlled study to investigate the therapeutic effect of vitamin B6 on carpal tunnel syndrome. After ten weeks in the study, ten of 15 patients improved (this included patients given placebo and those given no treatment). Vitamin B6 seems to have no advantage over conservative therapy for carpal tunnel syndrome. This study also suggests that repeat electrodiagnostic testing is no more useful than clinical symptoms in deciding on surgical intervention after unsuccessful conservative therapy.