Objective: In-office bleaching has become very popular for patients desiring immediate results. This report discusses the efficacy of in-office bleaching using high-intensity xenon halogen tungsten light on 73 patients in a private practice over 6 months. Method and materials: Thirty-five percent hydrogen peroxide gel was applied to the tooth surfaces, and then both arches were illuminated with the LumaArch unit light for 8 minutes. The entire procedure was completed 3 times for a total application time of 24 minutes. Thereafter, patients returned every 2 weeks for another 24-minute in-office treatment until the patient was satisfied or did not want additional treatment. After completion of bleaching, patients were classified into groups according to the number of treatments they received. When requested, home bleaching was used as a follow-up treatment. The degree of color change and color relapse were evaluated at baseline and immediately, 2 weeks, and 6 months after bleaching. Also evaluated was the number of patients that requested home bleaching. Results: Of the 73 patients who received 1 to 4 in-office bleaching procedures, 58 were satisfied. Twenty-seven patients requested home bleaching. The average color change per appointment was 2.1 to 3.7 units on a 16-scale Vita Classic shade guide. Color relapse was more noticeable at the 2-week interval than at the 6-month postbleaching evaluation. Conclusion: In-office bleaching may be an alternative for patients who do not like home bleaching. In-office treatment may achieve satisfactory results, but often more than 1 visit is necessary to achieve patient satisfaction. Keywords: bleaching, high-intensity xenon halogen tungsten light, home bleaching, in-office bleaching, patient satisfaction, tooth whitening