The knowledge of major sources of macro- and micronutrients is essential in order to interpret differences in the diet-cancer link in various geographical areas and to provide better nutritional guidelines. For this purpose we took advantage of the control group of a case-control study on breast cancer carried out in six Italian areas. The dietary habits of 2,588 cancer-free women aged 20-74 years (median age 56) were elicited between 1991 and 1994 by means of an interviewer-administered food frequency questionnaire (FFQ) that included 78 foods or food groups, in addition to several questions on general dietary pattern (e.g., fat in seasoning). Bread was the first contributor for total energy (12%), protein (8%) and starch (32%) intake, whereas, for saturated fatty acid, the first sources were different types of cheese (28%); for monounsaturated fatty acids the dressing oils of salad and tomatoes (12%); and, for sugars, apples and pears (19%). Raw vegetables and fresh fruit represented the most important source of most vitamins. The first contributors of vitamin C and beta-carotene were citrus fruits (29%) and raw carrots (17%), respectively. Thus, between 40 and 80% of specific macronutrient intake and up to 90% intake of several micronutrients were derived from the first ten foods or food groups. Often, the major contributors to the intake of a specific component were foods with a relatively low content, but eaten in large quantities. This work further highlights the specificity of nutrient sources in southern European populations.