From the Scottish Melanoma Group database for south-east Scotland we evaluated 5-year follow-up in patients with cutaneous malignant melanoma excised between 1979 and 1994 and devised an 'evidence-based' review protocol. Of the 1568 with stage I melanoma, 293 (19%) developed a recurrence, 32 had a second primary melanoma and 97 had an in-situ melanoma. The disease-free interval shortened progressively with increasing tumour thickness. Overall, 80% of recurrences were within the first 3 years, but a few patients (< 8%) had recurrences 5 or 10 years after the initial surgery. In-situ melanomas did not recur. Almost half (47%) the recurrences were noted first by the patient, and only 26% were detected first at a follow-up clinic. One hundred and thirty-nine patients (89%) were still under review when their recurrences were detected, and 102 (65%) had been seen within the previous 3 months. Questionnaires were completed by 120 patients: sun protection and avoidance, and mole examination were more likely after melanoma excision. We recommend 3-monthly review of patients with invasive lesions for the first 3 years. Thereafter, those with lesions >/= 1.0 mm need two further annual reviews. Patients with in-situ lesions should be reviewed once, to confirm adequate excision (0.5 cm margins) and to give appropriate education. Surveillance beyond 5 years is only justified if there are special risk factors.