Many drugs that were not designed to treat cardiovascular diseases may affect the cardiovascular system, causing adverse reactions. The objective of this chapter is to review in a systematic manner these adverse effects of non-cardiovascular drugs. The heart consists of four main entities that may be affected by non-cardiovascular drugs and lead to very different types of events: (1) the conduction tissue, that governs heart rate and rhythm, associated with arrhythmia and sudden death; (2) the endocardium and valves, associated with valvular disease and endocardial fibrosis; (3) the myocardium, which can directly or indirectly lead to heart failure; and (4) the coronary arteries, and in general the vascular bed, with myocardial ischaemia and infarction as main adverse events. These different elements may be affected by different drugs with different mechanisms of action, though some drugs may affect several components (e.g. myocardial infarction may result in heart failure). The objective of this chapter is not to provide exhaustive listings of all drugs ever associated with any of these events, which can be found online and will be obsolete the moment they are published, but an understanding of the typology of these events and their mechanism.