Pigmented nevi, if excised incompletely, often recur and occasionally cause concern to the patient and the physician. In this study of 175 recurrent nevi from 173 patients, the clinical, gross, and microscopic features of recurrent nevi are described and criteria for diagnosis are developed. Rarely, recurrent nevi have atypical features that suggest malignant melanoma. The differential diagnosis entails clinical and histologic criteria that are presented.