Background: The term dysplastic nevus as introduced by Clark has been considered to refer to a precursor lesion of melanoma by some authors and to the commonest acquired nevus by others. Objectives: To clarify the relationship between so-called dysplastic nevi, Clark's nevi, and congenital nevi. Patients/Methods: Review of the literature pertinent to the subject of dysplastic nevi in historical perspective. Results: Clark and coworkers claimed to have studied a specific acquired melanocytic nevus designated by them, consecutively, B-K mole, large atypical mole, and dysplastic nevus. Most of the large "dysplastic" nevi they pictured in photomicrographs, however, are superficial congenital nevi. Conclusions: We suggest that the small, flat or very slightly raised, acquired, pigmented benign proliferations of melanocytes be referred to as "Clark's nevi" and the larger, discernibly elevated, pigmented benign proliferations of melanocytes be designated "superficial congenital nevi."