Two patients with cutaneous metastatic melanoma were treated with a topical retinoid, beta-all-trans-retinoic acid. Complete regression of the treated lesions was noted in one patient and a partial response was seen in the other patient. The mechanism of anti-tumour action of the retinoids is not completely known but binding to intracytoplasmic receptors with promotion of cellular differentiation, alteration of membranes, and immunological adjuvant effects may be involved.