OBJECTIVE: To evaluate the therapeutic efficacy of acitretin in patients with isolated nail psoriasis. DESIGN: Open study involving 36 patients with moderate to severe nail psoriasis treated with acitretin. SETTING: University-based outpatient dermatology clinic specializing in nail diseases. PATIENTS: A total of 27 men and 9 women (mean age, 41 years) with nail psoriasis. INTERVENTION: Therapy consisted of acitretin, 0.2 to 0.3 mg/kg/d, for 6 months. MAIN OUTCOME MEASURES: Clinical evaluation, and Nail Psoriasis Severity Index (NAPSI) and modified NAPSI scores before therapy, every 2 months during therapy, and 6 months after treatment. RESULTS: The mean percentage of reduction of the NAPSI score after treatment was 41%; the mean percentage of reduction of the modified NAPSI score of the target nail was 50%. Clinical evaluation at 6 months showed complete or almost complete clearing of the nail lesions in 9 patients (25%), moderate improvement in 9 (25%), mild improvement in 12 (33%), and no improvement in 6 (11%). CONCLUSION: Results from low-dose acitretin therapy show NAPSI score reductions comparable with those studies evaluating biologic drugs for nail psoriasis and suggest that low-dose systemic acitretin should be considered in the treatment of nail psoriasis.