Try as some might, it has proved exceedingly difficult to dispel the notion that primary melanoma should be treated by arbitrarily wide resection margins. There was never any substantive scientific foundation for the traditional 5-cm margin, but for much of this century it nevertheless found favor in medical folklore. Current opinions concerning melanoma management in the dermatologic literature, while careful to point out the limitations of supportive data, have continued the tradition of offering arbitrary guidelines for resection margins. The last 2 decades have witnessed the acquisition of sufficient experimental evidence to warrant further scrutiny of the practice.