Background: Therapy for Bowen's disease is essential to prevent invasive squamous cell carcinoma and metastases. Surgical excision is preferred because of the low relapse rate, but it may result in scar contracture, especially in the digit. Objective: This study was undertaken to evaluate the effectiveness of carbon dioxide laser for Bowen's disease of the digit. Methods: Patients with biopsy-proven Bowen's disease of the digits were recruited from the Department of Dermatology, Siriraj Hospital during the period 1992-1998. Risk factors were assessed. The lesion and 4 mm of surrounding clinically uninvolved skin were vaporized by means of the carbon dioxide laser. Wounds were managed by second intention. Patients were followed up at 1 week, 4 weeks, 6 months, and yearly thereafter if applicable. Results: During this 7-year period, only 6 patients with Bowen's disease of the digits were identified. Four of the 6 had a long history of exposure to arsenic from herbal medicines. Postoperative clinical appearance was mild atrophic skin and hypopigmentation. No functional impairment was found. Biopsy specimens taken after treatment showed a slightly thinned epidermis and mild fibrosis in the papillary dermis. There has been no evidence of recurrence in the 6 months to 7.7 years since surgery. Conclusion: At least 67% of the patients affected by Bowen's disease of the digits had chronic arsenicism. It may be the earliest presentation of chronic arsenicism. Carbon dioxide laser provides ease of surgery, excellent cosmesis, preservation of function, and effective treatment for patients with Bowen's disease of the digits. (J Am Acad Dermatol 2000;43:1080-3.)