The traditional Mediterranean diet, as studied in the 1950s to 1960s in the South of Europe, is characterized by moderate energy intake, low animal fat, high olive oil, high cereals, high legumes, nuts and vegetables, and regular and moderate wine. A Mediterranean-type diet is being developed to mimic the traditional one and fit with present life style. While numerous epidemiological studies have supported the concept that adherence to the traditional Mediterranean diet is beneficial for health and particularly protects against cardiovascular disease, the limited number of intervention studies in this field have not yet provided major support. Nevertheless, the dietary interventions performed until now have demonstrated that adoption of a Mediterranean-type diet reduces several cardiovascular risk factors in subjects at risk (primary prevention) and/or cardiovascular events or mortality in patients after a first cardiac event (secondary prevention). Among numerous foodstuffs characterizing the Mediterranean diet, virgin olive oil has been shown to display beneficial effects on a wide range of risk factors.