Radiation was used extensively for the treatment of all types of infections before the advent of antibiotics. Although this mode of therapy is now in disrepute, radiation therapists of that era were firm believers in the ability of radiation to cure infections. A review of the literature suggests, but certainly does not prove, that low-dose local radiation, in the range of 75 to 300 roentgens, is an effective treatment modality for a wide variety of infections. Two then-prevailing rationales held that the effect was due either to radiation damage to the immune cells, causing stimulation of the immune response, or to the increase in local inflammation with resultant increased blood flow. Modern research has been limited but provides support for both arguments. Although there are no present indications for using radiation as therapy for infectious disease, a reasonable argument can be made from the available data that radiation is effective for the treatment of localized infections. The mechanisms of low-dose radiation as a treatment for infections remain unclear. The known and probable long-term sequelae of low-dose local irradiation preclude its common use for this condition. Nevertheless, it is hoped that this review will stimulate investigations into this relatively unexplored area of radiobiology.