The relationship between coffee consumption and blood lipids was analyzed in a sample of 900 male workers of southern Italy participating in the Olivetti Heart Study. In the univariate analysis, coffee drinkers (n = 856) had higher values for body mass index (P < or = 0.05) and number of cigarettes smoked per day (P < or = 0.001) and lower levels of serum high-density-lipoprotein cholesterol (P < or = 0.05), compared to noncoffee drinkers (n = 44). In addition, coffee consumption (cups/d) was positively related to serum triglyceride levels (r = 0.105, P < or = 0.01) and cigarette smoking (r = 0.491, P < or = 0.01), and was inversely related to age (r = -0.122, P < or = 0.01). After multivariate adjustment, coffee consumption remained significantly related to age, cigarette smoking, and body mass index (data not shown). After stratification for smoking status, a significant positive linear trend between coffee consumption and serum total cholesterol was observed only in smokers. No significant trend was observed for serum triglycerides and high-density-lipoprotein cholesterol with coffee intake according to smoking status. This finding suggests that the relationship between coffee consumption and serum total cholesterol may change with the smoking status.