T-cell large granular lymphocytic leukemia (T-LGL) is a rare disorder, characterized by a chronic course, autoimmune manifestations and autoantibodies, cytopenias and circulating cytotoxic T-lymphocytes. T-LGL leukemia usually manifests with hematological involvement and co-existing autoimmune and/or autoinflammatory conditions. Behcet's disease (BD) is a chronic inflammatory disorder with recurrent oral and genital ulcers, uveitis, other systemic findings such as neurologic involvement, vasculitis and arthritis. Pathogenesis of BD is still poorly understood. However, a polarization of the Th1/Th2 immune response toward the Th1 pathway, and Th17 involvement have been shown. Herein, we present two cases of T-LGL co-existing with BD, second and third cases in the literature. We review, discuss and hypothesize a possible pathogenetic association between BD and T-LGL.