Background: Despite refinements in the diagnosis of cutaneous T-cell lymphoma (CTCL), since 1979 there have been no changes to the staging of CTCL used to classify mycosis fungoides and Sézary syndrome. Objective: We reviewed the current staging of CTCL and examined the usefulness of a new staging scheme for mycosis fungoides and Sézary syndrome. Methods: We determined overall survival of 450 patients with mycosis fungoides and Sézary syndrome using the current and modified staging classifications. Results: There were no significant differences between survival of patients with stage IB (patches/plaques involving greater than 10% body surface area) and IIA (peripheral adenopathy) disease and of patients with stage IIB (tumor) and III (erythroderma) disease. There was a significant difference in survival between patients with extensive patch versus extensive plaque stage disease. Modification of the current classification by splitting T2 into patch versus plaque stage disease and incorporating tumors and erythroderma into stage III proved superior to the current scheme in predicting overall survival. Conclusion: Modification of the current staging classification for CTCL yields subgroups useful in the prognostic assessment of CTCL. (J Am Acad Dermatol 2001;45:700-6.)