The etiologic role of viruses in cutaneous lymphoproliferative disorders is still controversial. In benign cutaneous pseudolymphomas of the human skin, human T-cell leukemia/lymphoma virus (HTLV) type I (HTLV-I), varicella zoster virus, Epstein-Barr virus (EBV), and human herpesvirus (HHV) 6 (HHV-6) are the viruses most often identified, whereas in malignant lymphoproliferation human immunodeficiency virus type 1 (HIV-1), HTLV-I/II, and EBV are more common. Coinfections with more than one virus species have occurred in a number of cases. HHV-8 in association with a lymphoproliferative lesion appears to be indicative of a malignant cutaneous lymphoma rather than of pseudolymphoma. Negative results are of no diagnostic value because of the relatively low number of virus-positive cases: a considerable proportion of studies (with a large number of subjects) have documented virus-negative findings. Perhaps with the exception of HIV-1, findings of viral infections seem to indicate secondary rather than primary infections. Reports on animal models associated with human pathogenic viruses are scarce.