The syndrome of idiopathic CD4+ T lymphocytopenia (ICTL) is defined as the persistent depletion of peripheral blood CD4+ T lymphocytes below 300 cells/mm(3) or less than 20% of the total lymphocytes in the absence of either HIV infection or other known causes of immunodeficiency. To date no known viral origin has been identified. ICTL has a variable clinical course ranging from patients with minimal symptoms to those who have died from opportunistic infections. We report a case of a 32-year-old white man with a long history of vitiligo that is associated with ICTL. He also had incidental psoriasis. The correlation between ICTL and autoimmune vitiligo suggests an aberration in the immune surveillance that leads to an abnormal response of CD4+ T lymphocytes in the host.