If lightning strikes an explosive or blasting circuit, detonation is very probable regardless of the precautions taken. Even a near miss will probably cause a detonation. Many studies have shown that a lightning strike can initiate electric blasting caps several miles away. Only a direct strike will initiate nonelectric initiation systems. When explosives prematurely detonate, the chances of death or serious injury are very high. Since 1962, premature initiations caused by lightning killed at least 10 miners and injured 17; 31 incidents were reported. More incidents have occurred but, quite often, when no one was hurt, the incident went unreported. U.S. Bureau of Mines accident studies report that lightning was reponsible for 16 out of 80 premature initiations of explosives from 1978 to 1985, more than any other single cause. This paper reviews the lightning warning systems available to the mining industry.