Introduction: Sezary syndrome (SS) is a rare leukemic variant of cutaneous T-cell lymphoma (CTCL) comprising 3 - 10% of all CTCLs. Patients present clinically with erythroderma defined as confluent pink or red skin with or without scaling that must involve at least 80% of the body surface area. SS requires the presence of a dominant T-cell clone plus one of the following: an absolute Sezary cell count of 1000 cells/mm(3) or higher, expanded CD3(+) or CD4(+) cells with a CD4/CD8 ratio of 10 or higher, or expanded CD4(+) T cells with abnormal immunophenotype including loss of CD7 or CD26. Areas covered: This review summarizes the various therapies for SS including first-line, second-line, third-line and palliative treatments. Extracorporeal photopheresis, IFN alpha and gamma, as well as bexarotene are generally accepted first-line therapies to consider for the initial treatment of SS. Expert opinion: Early SS patients, including patients with B1 involvement and erythroderma, should get combined immunomodulatory therapy, avoiding immunosuppressive therapy. There is a trend toward the development of targeted therapies that are selected for individual patients based on understanding which mutations, genetic alterations and pathways need to be targeted by therapy. For immunocompetent patients < 65 years old, allogeneic stem-cell transplantation may result in complete remissions or cures.