The present review discusses and summarizes the up-to-date body of knowledge concerning human nutrigenomic studies with Mediterranean diet (MedDiet) and olive oil (OO) interventions, at real-life doses and conditions. A literature review was carried out until March 2012. Original articles assessing the nutrigenomic effect of the MedDiet and its main source of fat, OO, on gene expression were selected. State-of-the-art data in this field, although scarce, are promising. Despite a great diversity among studies, the attributed health benefits of the MedDiet and its components, such as OO, could be explained by a transcriptomic effect on atherosclerosis, inflammation, and oxidative stress-related genes (i.e. ADRB2, IL7R, IFNγ, MCP1, TNFα). Gene expression changes toward a protective mode were often associated with an improvement in systemic markers for oxidation and inflammation. The suggested underlying molecular pathways responsible for these changes, and the extent to which evidence exists of a MedDiet and OO nutrigenomic effect, are also discussed.