We studied the associations between 11 scales of social functioning and risk of death over an average follow-up time of 71 months in 42- to 60-year-old men in the Kuopio Ischemic Heart Disease Risk Factor Study. In age-adjusted analyses, men were at increased risk of death if they reported few persons to whom they gave or received social support, nonparticipation in organizations, low quality of social relationships, a small number of friends, or not currently being married. Frequency of interaction, shyness, and use of emotional support when troubled were not associated with risk of death; the use of instrumental support when troubled was associated with increased risk. There was little evidence of confounding of these associations by the presence of 31 chronic or acute conditions, perceived health status, or six risk factors. Consistent associations were found in a healthy subgroup. These data add to the growing body of literature linking mortality risk with social functioning, especially in relation to organizational participation and quality of relationships.