We used data from the 1993 Italian Household Multipurpose Survey, based on a sample of 46,693 subjects ages 15 years or over, to analyze the relation between frequency of vegetable consumption and prevalence of 12 chronic diseases. We observed little association with diabetes mellitus, hypertension, and allergy. There were inverse relations between vegetable consumption and myocardial infarction [odds ratio (OR) = 0.79 for the highest tertile], angina pectoris (OR = 0.89), chronic bronchitis (OR = 0.69), bronchial asthma (OR = 0.70), peptic ulcer (OR = 0.74), gallstones (OR = 0.92), liver cirrhosis (OR = 0.71), kidney stones (OR = 0.68), and arthritis (OR = 0.84). Adjustment for alcohol and tobacco use made little difference.