A 30-year experience with 31 cases of squamous cell carcinoma arising in scars is reviewed. Mean age of the patients was 58 years. Average time from injury to diagnosis was 23 years. The male to female ratio was 4:1. Tumors were well differentiated in 23 cases and poorly differentiated in eight cases. Three-year survival rate was 94% for patients with well-differentiated lesions, but only 38% for those with poorly differentiated ones which were more likely to metastasize. Implications of these findings are discussed in relation to therapy.