Background: Data illustrating the impact of atopic dermatitis (AD) on lives of adults with AD in South Korea are limited. Objective: To assess the AD disease severity and its impact on quality of life (QoL) in patients with AD from South Korea. Methods: Patients with AD utilizing the specialist dermatology services of major hospitals in South Korea were assessed for disease severity using Eczema Area and Severity Index (EASI) score, for QoL using Dermatology Life Quality Index (DLQI) (for QoL), and for comorbidities and treatment experience via retrospective review of 12-month medical records. Clinical and sociodemographic characteristics were also measured. Results: Of the 1,163 patients, 695 (59.8%) were men (mean age years±standard deviation: 31.6±12.1). Overall, 52.9% (n=615) patients had moderate-to-severe disease (EASI>7). The QoL of 72.3% (n=840) patients was affected moderately-to-severely (DLQI score: 6~30). Systemic immunosuppressants were used ≥1 over past 12 months in 51.9% (n=603) patients, and the most commonly used were cyclosporines (45.7%, n=531) and systemic corticosteroids (40.5%, n=471). Approximately, 10.8% (n=126) patients consulted or received treatment for AD-related eye problem. Of these, 40% (n=50) patients reported poor, very poor, or completely blind status; approximately, 16.7% patients (n=192) reported having depression or anxiety; and 35.5% (n=410) reported suicidal ideation or suicidal attempt. Conclusion: A large proportion of patients had moderate-to-severe AD, a compromised QoL, and ocular or mental health comorbidities, indicating a high disease burden despite systemic treatment. These findings highlight the importance of a holistic approach for the evaluation and treatment of patients with AD.