Cardiotoxicity, including acute and late-onset cardiotoxicity, is a well-known adverse effect of many types of antitumor agents. Early identification of patients with cardiotoxicity is important to ensure prompt treatment and minimize toxic effects. The etiology of chemotherapy-induced cardiotoxicity is multifactorial. Traditional methods for assessment of chemotherapy-induced cardiotoxicity typically involve serial measurements of cardiac function via multi-modality imaging techniques. Typically, however, significant left ventricular dysfunction has already occurred when cardiotoxicity is detected by imaging techniques. Biomarkers, most importantly cardiac natriuretic peptides and troponins, are promising markers for identifying patients potentially at risk for clinical heart failure symptoms. This review summarizes the recent progress in clinical utilization of biomarkers for early diagnosis of acute cardiotoxicity and for prediction of late-onset cardiotoxicity. We also discuss the conflicting results of different studies and the association of results with study design.