The T-cell Lymphoma Forum was held from 28-30 January, 2010, in Maui, HI, USA. The meeting provided a venue for clinicians and scientists to discuss the science and treatment of T-cell and natural killer (NK)-cell lymphomas. Different subtypes of T-cell and NK-cell lymphomas have different epidemiologic and clinicopathologic characteristics. T-cell and NK-cell lymphomas are more prevalent in Asian countries; however, cutaneous T-cell lymphomas are more prevalent in Western populations. The definition of pathogenetic signaling pathways and viral associations form the basis of the design for the treatment specific to these lymphomas. Therapeutic targets include surface antigen expression, cytokine signaling, epigenetic aberrations and the lymphoma microenvironment. The combination of novel therapeutic agents with chemotherapy, and the judicious use of high-dose chemotherapy and hematopoietic stem cell transplantation, may improve the outcome of patients with T-cell and NK-cell lymphomas.