Concern over the possible hazards of cxposurc to microwave radiation has lately been on the incrcase. Increasing industrial and commercial use of microwave generators for heating and cooking, increasing power of radar scts, and expansion of the broadcasting industry have resulted in more widespread interest in the possible biological eKccts of these electromagnetic radiations. A critical review of the literature on biological effects ofmicrowave irradiation is presented along with an analysis of the present status of standards and hazard evaluation.