Background: Ashy dermatosis is a disorder of pigmentation, characterized by asymptomatic symmetric blue-graycolored macules of unknown pathophysiology. Objective: Our aim was to evaluate ashy dermatosis in Koreans and to describe its clinical and histopathological features. Methods: Medical records, photographs, and biopsy specimens obtained from 74 patients were assessed. Results: Of the 74 patients, 38 were men and 36 were women. Clinically, most patients showed lesions on the trunk (83.8%), followed by the extremities (44.6%). At the time of the mean age was 29.9 years, and disease duration was 18.4 months before the institution. We tentatively classified the lesions into the following 3 groups: generalized confluent, generalized macular, and localized type. Clinically, the most common lesion was the generalized macular type (67.6%). Peripheral erythematous borders or concomitant erythematous lesions were observed in 18 patients (24.3%). Histopathologically, the lesions showed perivascular inflammation, dermal melanophages, and pigmentary incontinence. Conclusion: Our study classified ashy dermatosis into 3 groups, and this categorization may contribute to a better understanding of ashy dermatosis.