Chemotherapy is a well-established therapeutic approach for several malignancies, but its clinical efficacy is often limited by its related cardiotoxicity, which leads to cardiomyopathy, possibly evolving into heart failure. To detect cardiac damage, the adopted diagnostic approach is the estimation of left ventricular ejection fraction by echocardiography. This approach shows low sensitivity toward early prediction of cardiomyopathy, when the possibilities of appropriate treatments could still improve the patient's outcome. Cardiac troponins, however, show high diagnostic efficacy as early as 3 months before the clinical onset of cardiomyopathy. The increase in their concentrations is correlated with disease severity and may predict the new onset of major cardiac events during follow-up. Negative troponin concentrations may identify patients with a very low risk of cardiomyopathy (negative predictive value, 99%). Concerning cardiac natriuretic peptides, definitive evidence in regard to a diagnostic or prognostic role in predicting chemotherapy-induced cardiomyopathy is still lacking.