The infections due to herpes-varicella viruses occurring in 191 patients with Hodgkin's disease form the basis of this report. There were overall 41 episodes (26.7%) in 40 patients, distributed as follows: varicella in three cases, atypical herpes-varicella in two cases, and herpes zoster in 36 cases, the latter showing systemic spread in seven instances, one to the central nervous system (myelitis) and six to the skin. The mortality was 2.5% of all infections, and 33% of the varicella cases. Morbidity was apparent as postherpetic neuralgia in seven patients (19.4%), postherpetic paraplegia in one case (2.5%), and severe thrombocytopenia in another case (2.5%). The statistical study of the factors contributing to the development of reactivation episodes demonstrated that neither age, sex, or previous splenectomy were influential. The results obtained in relation to the stage and histologic type of Hodgkin's disease can not be fully evaluated because of the artifact introduced by other variables such as type of therapy and observation time. There was a clear relationship with the aggressiveness of therapy, because 81.7% of the viral episodes occurred in patients submitted to total radiotherapy with or without chemotherapy, or with partial radiotherapy plus chemotherapy. In the patients with systemic spread there was a clear relationship with prior splenectomy (p less than 0.005). The clinical features of these patients are commented upon.