Onychomycosis is a common disease seen in dermatology practice. Most patients with onychomycosis opt for treatment due to the social stigma attached to the unsightly appearance, as well as the pain that can at times make walking difficult. However, in many cases, onychomycosis is resistant to oral antifungal medication, which is the first-line therapy for this disease. In recent years, we have attempted a new treatment method using a long-pulsed 1,064nm Nd :YAG laser (Cutera Inc., Brisbane, CA, USA) in refractory cases with onychomycosis. Using 1) a laser beam with a spot size of 5.0 mm and 2) sequential irradiation at low fluence, we 3) applied the laser to the infected lesions in a motion similar to showering, while maintaining a distance of several centimeters from the skin (Laser Genesis(TM)). Treatment efficacy was assessed using nail turbidity scores on a five-point scale. Improvement in onychomycosis was noted in more than 68.8% of all cases, thus demonstrating the high efficacy of this method. No major adverse reactions were observed during the treatment period. Since its mechanism of action clearly differs from that of antifungal agents, it can be considered a useful treatment option for cases with onychomycosis resistant to antifungal therapy. Future studies should examine "combined therapy" with oral / topical antifungal agents and this laser treatment, which may provide a significant improvement in the level of satisfaction among patients with onychomycosis.