The biological effects of specific interactions occurring between drugs and foods may greatly vary, determining severe side effects in some people. A lot of factors may influence such interactions, i.e. age, sex, dietary composition, and so. In addition, further interaction may be determined by cigarette smoking, alcohol abuse and coffee consumption. Older people, as well as children, chronic ill and malnourished people seems to be most commonly affected by side effects due to food/drugs interaction. The aim of this review is to give a synopsis of the drug/food interactions most commonly occurring in clinical practice.