The X-ACT (Xeloda in Adjuvant Colon Cancer Therapy) trial compared the efficacy and safety of the oral fluoropyrimidine capecitabine with bolus 5-fluorouracil (5-FU)/leucovorin (LV; Mayo Clinic regimen) as adjuvant therapy for stage III colon cancer. A total of 1987 patients were enrolled at 164 centers worldwide. Disease-free survival (primary study endpoint) in the capecitabine arm was at least equivalent to that in the 5-FU/LV arm; the upper limit of the hazard ratio was significantly (P < 0.001) below the predefined margins for noninferiority. Capecitabine was also associated with significantly fewer fluoropyrimidine-related grade 3/4 adverse events (AEs; P < 0.001) and fewer AE-related hospital admissions/days than 5-FU/LV. Pharmacoeconomic analyses performed in several countries show that the savings in direct costs (drug administration and AE-related costs) associated with capecitabine versus 5-FU/LV offset the acquisition costs of the drug. Furthermore, capecitabine reduces patient travel time and costs, making it a "dominant" strategy (ie, less costly and more effective) in the adjuvant setting. In conclusion, efficacy, safety, convenience, and cost findings from the X-ACT trial show that capecitabine offers at least equivalent clinical benefit compared with bolus 5-FU/LV and can replace intravenous 5-FU/LV in the adjuvant treatment of stage III colon cancer. The X-ACT trial has not only helped to better define the role of capecitabine but has also broadened the options available to patients with early-stage disease to include a uniquely effective oral outpatient treatment.