The purpose of this review article is to inform practicing cardiologists about the manifestations of cardiotoxicity in patients on or after antitumor therapy and about the potential of cardiac magnetic resonance imaging (CMR) in the diagnosis and follow-up of these patients. The definitions and classification of cardiotoxicity associated with antitumor treatment, the mechanisms of cardiac and vascular damage of some of the important groups of antitumor drugs, and the potential CMR findings are reviewed. The main clinical situations related to manifestations of cardiotoxicity in which CMR has or is expected to have a leading role are outlined.