Understanding differences in dietary patterns by smoking status is important for nutritionists and health educators involved in helping individuals to make healthy dietary and lifestyle choices. Although smokers have a poor quality diet compared with nonsmokers, no study has examined nutritional adequacy and variability in the nutrient intake of smokers. The aim of this study was to compare dietary habits of smokers with nonsmokers in terms of nutrient intake, food groups contributing to nutrient intake, nutritional adequacy and day-to-day variation in nutrient intake. Noninstitutionalized adults aged 18--65 y (n = 1543) who participated in the Food Habits of Canadians Survey (1997--1998) were studied. Subjects, selected from across Canada using a multistage, random-sampling strategy, completed an in-home 24-h dietary recall. Repeat interviews were conducted in a subsample to estimate variability in nutrient intake. Smokers had higher intakes of total and saturated fat, and lower intakes of folate, vitamin C and fiber than nonsmokers. There were no significant differences in calcium, zinc and vitamin A intakes or day-to-day variation in nutrient intake by smoking status. Smokers consumed significantly fewer fruits and vegetables than nonsmokers, leading to lower intakes of folate and vitamin C. In conclusion, smokers have a less healthy diet than nonsmokers, placing them at higher risk for chronic disease as a result of both dietary and smoking habits. Diet may act as a confounder in smoking-disease relationships.