A total of 472 patients with clinical Stage I cutaneous melanoma were analyzed to determine influence of type of diagnostic biopsy on survival. Of these patients, 119 had had an incisional biopsy (either punch or incision) and 353 had an excisional biopsy. Patients were grouped by thickness category and outcome compared between the biopsy types. Within each thickness category, there is no statistically significant difference in survival between the two groups. The observation that none of the seventy-six patients with primary tumors less than 1.70 mm have died following incisional biopsy strongly argues against any deleterious effect of incisional biopsy in this group. Alternatively, if the two highest-risk groups (greater than or equal to 1.70 mm) are analyzed as a single group, an adverse effect is seen in the incisional biopsy group (p less than 0.05). However, when the data from these groups are subjected to multivariate analysis, biopsy type is not a significant factor in the model. This study shows that either biopsy method may be used in first evaluating patients with suspected melanoma.