Objective: Accumulating evidence exists for (1) an inverse correlation between the incidence of infectious diseases and cancer risk and (2) an inverse correlation between febrile infections and remissions of malignancies. This review is part of an effort of the Office of Alternative Medicine at the National Institutes of Health to examine this evidence. Methods: A review of the literature to a key word search was undertaken, using the following key words: fever, infectious diseases, neoplasm, cancer incidence and spontaneous remission. Results: The data reviewed in this article support earlier observations on the topic, i.e. that the occurrence of fever in childhood or adulthood may protect against the later onset of malignant disease and that spontaneous remissions are often preceded by feverish infections. Conclusion: Pyrogenic substances and the more recent use of whole-body hyperthermia to mimic the physiologic response to fever have successfully been administered in palliative and curative treatment protocols for metastatic cancer. Further research in this area is warranted.