Our aim is to study unanticipated cardiotoxicity associated with the use of anticancer targeted agents, a problem that remains poorly understood. Using diagnosis codes, we retrospectively identified patients with both hematologic malignancies (HM) and cardiovascular diseases (n = 820 patients). Cardiotoxicity was defined per published criteria. The targeted agents of interest included tyrosine kinase inhibitors, proteasome inhibitors, monoclonal antibodies, and immunomodulatory agents. Patients found with cardiotoxicity (n = 29) were compared with 70 case-matched reference subjects. Median time from targeted therapy exposure to cardiotoxicity was 132 days. A higher percentage of patients had prior exposure to anthracyclines in study versus reference group (65.5 vs. 42.8%, P = 0.04), however, did not stay significant in multivariate analysis. Two variables were significant predictors, prior of DVT/PE and Karnofsky score of ≥ 80% (P ≤ 0.011). Only 2 study group patients died of cardiac causes. Most cardiotoxicity patients (23/29) had remained stable or improved, while 21 patients received further chemotherapy. OS was lower in the study group (P = 0.018) versus the reference group. In conclusion, a small number patients with HM experience unanticipated cardiotoxicity with low related mortality. Risk of cardiotoxicity was significantly associated with history of DVT/PE. Most patients do well, but despite that, their OS is significantly poorer.