Metal welding and cutting are associated with inhalation of gases and respirable particles. The purpose of this study was to compare the mortality of male welders with that of all gainfully employed men in Sweden regarding ischemic heart disease (IHD). Male welders and gas cutters were identified in the Swedish National Censuses of 1970 and 1990. Two cohorts were established and followed until the end of 1995. The IHD mortality among the welders was compared with that of all gainfully employed men. An increased mortality due to IHD was observed among welders identified in the 1990 Census, SMR = 1.35, 95% confidence limits 1.1-1.6. The observed increased mortality due to IHD was unlikely to be explained by different smoking habits. A general hypothesis linking inhalation of particles to the occurrence of IHD via an inflammatory process is discussed.