Background: Chronic actinic dermatitis is a rare, acquired, persistent eczematous eruption of photo-distributed areas. There are limited data available on the clinical characteristics of Korean patients diagnosed with chronic actinic dermatitis. Objective: To evaluate the clinical features and prognosis of chronic actinic dermatitis patients in Korea. Methods: Sixty-two Korean patients diagnosed with chronic actinic dermatitis through clinical findings, phototesting, and skin biopsy from six hospitals were included in this study, and their clinical characteristics were evaluated. Results: Among the 62 patients, 51 were men, and the mean age at diagnosis was 60.3±12.8 years. Phototesting was performed for 27 patients, with results available for 18 patients. Patch tests were performed for only 4.8% of the patients. Skin pathology tests were performed for 47 patients and showed the following: spongiosis, acanthosis, actinic elastosis, and pseudo-lymphomatous change. Twelve patients were clinically diagnosed without using diagnostic tools such as phototesting, patch testing, and skin biopsy. The most commonly used systemic treatments were antihistamine, cyclosporine, steroid, and azathioprine. Although avoiding ultraviolet irradiation and outdoor activities are critical, only 22.6% of patients used sunscreen. Conclusion: Although phototesting is highly recommended for diagnosing chronic actinic dermatitis, phototesting was performed for less than half of the patients to diagnose chronic actinic dermatitis. Patch tests and photopatch tests are also recommended to disclose a causative agent. (Korean J Dermatol 2020;58(10):674∼680)