At the time of diagnosis primary cutaneous lymphomas are limited to the skin. T-cell lymphomas represent at least two thirds of all primary cutaneous lymphomas with mycosis fungoides and Sézary syndrome being the most frequent entities. A precise staging based on clinical, histological, immunohistological and molecular biological criteria is crucial for selecting the appropriate therapy. Since curative treatment is only possible in exceptional cases, the aim of any therapy is to achieve healing of the skin lesions, minimizing relapses, preventing progression and maintaining the quality of life. While in early disease stages skin-directed therapy is being used, in later stages systemic treatments become more important. This work aims to provide an overview of established and new therapies for the treatment of mycosis fungoides and Sézary syndrome.