The prevalence of nail psoriasis varies considerably among different studies, ranging from 10% to 55%. In psoriatic arthritis, its prevalence is as high as 85%. In spite of the high prevalence of the disease, considerable functional, psychical and cosmetic discomforts for the affected patients, and recent advances in the management of skin psoriasis, an efficacious and longlasting treatment for psoriatic nails remains elusive. A 51-year-old male patient with skin psoriasis and severe psoriatic lesions of all his finger nails and toe nails is presented. Some nail plates were up to 30 times thicker than normal. The patient received radiotherapy with soft x-rays in a total dose of 13.5 Gy administered in nine fractionated doses of 1.5 Gy (43 kV, 25 mA, 0.6 mm aluminum filter) at one-week and two-week intervals. Upon therapy completion, the appearance of nail plates gradually improved to normalize completely at 12 months of therapy. Almost three years of therapy completion, the patient is free from both disease relapse and radiotherapy sequels. Considering the high therapeutic efficacy and longlasting remission achieved, this type of radiotherapy should be used in the treatment of severe psoriatic nail lesions with massive nail plate thickening, to alleviate psychical and functional difficulties associated with the disease.