There have been conflicting reports concerning the relationship between increased alcohol intake and mortality from ischaemic heart disease. In this investigation, social register data also containing life-long registration data for alcoholic intemperance were related to cause of death for 302 men aged 35-44 in 1968-74. A random population sample of 940 male survivors of the same age was used for comparison. "Social problems only" were less common for the deceased, irrespective of cause of death, than for the controls. Registration for alcoholic problems was significantly more common for ischaemic heart disease, accidents, suicide and "other deaths" but not for cancer. The variables "detained by the police for drunkenness" and "in prison for crime" showed similar associations. Possible explanations are discussed, especially the association between alcoholic intemperance and death from ischaemic heart disease. The most probable mechanism is effects on the myocardial cell enzyme functions with following arrhythmias in subjects susceptible to malignant arrhythmias due to coronary artery disease and myocardial ischaemia.