General practitioners (GPs) in Denmark (n = 374) answered a questionnaire on attitudes toward including information on diet and sex in the prevention of coronary artery disease, cancers, osteoporosis, and weight problems. Risk factors for disease were ranked as follows: smoking, alcohol, stress, diet, physical exercise, heredity, and hygiene. Patients' lack of motivation, insufficient time for each patient, and inadequate knowledge about nutrition were listed by GPs as barriers to dietary counseling. GPs stated that the sex of the patient was important only for counseling on osteoporosis. Lack of time and insufficient knowledge were perceived as barriers to including sex-specific issues in prevention. One-half of the GPs were questioned about the issue of prevention on the basis of female case stories and the other half on the basis of male case stories with identical wording. Responses to the case stories indicated that GPs would give dietary guidance and recommend loss of weight to slightly overweight male patients to a much greater degree than to overweight female patients for prevention of coronary artery disease, give dietary counseling and recommend loss of weight and exercise to female patients more than to male patients for prevention of cancers, recommend a supplement of calcium and vitamin D for prevention of osteoporosis to female patients, and recommend weight gain and discuss psychosocial issues more with underweight female patients than with underweight male patients. Female GPs included measures of prevention such as dietary counseling, exercise prescription, dietary supplement prescription, and discussion of psychosocial issues to a greater extent than did male GPs.