Background: Sublingual immunotherapy (SLIT) with house dust mites (HDM) preparation has recently been proven to be beneficial for treating allergic rhinitis and asthma. However, there has been no report regarding the efficacy and safety of SLIT in Korean patients with atopic dermatitis (AD). Objective: We intended to investigate the efficacy and safety of SLIT in Korean patients with AD. Methods: A total of 34 patients with AD and immunoglobulin E (IgE)-proven HDM sensitization (Class >= 3) were recruited. Eczema area and severity index (EASI) score, total serum IgE level, specific IgE assays to Dermatophagoides pteronyssinus, D. farinae, and adverse effects were recorded during follow-up. "Responder" was defined as a patient with >= 30% improvement in EASI score after SLIT. Results: Twenty-three patients continued SLIT for 12 months or more, whereas 3 patients (8.8%) dropped out because of exacerbation of dermatitis, and 8 patients (23.5%) were lost to follow-up. The average duration of SLIT treatment was 22.4 months (range, 12 similar to 32 months). EASI scores reduced significantly after 6 months of treatment (p<0.05) compared with those at baseline. A total of 18 patients were determined to be responders to SLIT after 6 months. Total and specific IgE serum levels did not significantly reduce after SLIT. No patients experienced serious adverse events, with the exception of two patients who developed transient lip and tongue swelling. Conclusion: Our study demonstrated that SLIT with HDM extracts is effective and tolerable in Korean patients with AD. Further controlled long-term trials are required to reinforce the current results.