Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), is an umbrella term for lymphomas in the skin that cannot be classified into specific known subtypes. As such, PTCL-NOS is a diagnosis of exclusion that can be rendered only after an extensive clinical and histopathological evaluation has been performed. We present an erythrodermic patient from whom skin biopsies demonstrated an epidermotropic infiltrate of variably sized lymphocytes, including some large ones. Immunophenotyping demonstrated strong positivity among almost all of the lesional cells with CD3, CD7, and CD8 and moderate CD4 positivity in a minority of the lymphocytes. Despite positivity with GM3, a marker of γ/δ T cells, in almost all of the infiltrate, β-F1, a marker of α/β T cells, stained a sizable number of the larger lymphocytes. Gene rearrangement studies revealed a clonal population of T-cells using primers assessing both the T-cell receptor γ and β chain genes. Imaging studies revealed widespread lymphoadenopathy with nodes up to 1. 8 cm in diameter involving multiple lymph node basins. Flow cytometry from the peripheral blood revealed 2 populations of cells, with the major population positive for CD8 and negative for CD4 but with a minor population positive for both CD4 and CD8 (aberrant coexpression). Flow cytometry also revealed that almost all of the peripheral blood T cells were α/β T cells and not γ/δ T cells. The white blood cell count was 15.3 × 109. This patient’s lymphoma did not meet criteria for any known category of T-cell lymphoma, and therefore, the patient was diagnosed with PTCL-NOS. This case illustrates that the clinical presentation of erythroderma is not specific and does not equate with Sézary syndrome. Other forms of lymphoma, including PTCL-NOS, can present with erythroderma, as in this case. It also demonstrates the lack of specificity of epidermotropism among the T-cell lymphomas.