This paper describes a randomized parallel trial of topical 0.075% capsaicin versus vehicle (placebo) in the postmastectomy pain syndrome (PMPS). The study was double-blind in design; however, this was compromised by the burning sensation induced by capsaicin. We could not demonstrate a significant difference in the visual analogue scale (VAS) for steady pain although a trend was present. A significant difference was found, however, in the VAS for jabbing pain, in category pain severity scales, and in overall pain relief scales in favour of capsaicin. Five of 13 patients on capsaicin were categorized as good-to-excellent responses with 8 (62%) having 50% or greater improvement. Only 1 of 10 cases had a good response to vehicle with 3 rated as 50% or better.