To evaluate the contribution and performance of multimodal imaging in the diagnostic and therapeutic management of cardiac masses. We carried out a monocentric retrospective study on patients referred for cardiac mass assessment between 2006 and 2019, and analyzed the respective contribution of transesophageal echocardiography (TEE), cardiac computed tomography (CT), cardiac magnetic resonance (CMR) and 18 F-fluorodeoxyglucose positron emission tomography coupled with CT ( 18 F-FDG PET-CT). For each test, we determined strategy before and after its completion (need for another imaging or decision-making) as well as result on benign, malignant or indeterminate nature. For the 119 patients included, all imaging modalities increased decision-making rates, which rose from 2 to 54%, 23 to 62%, 31 to 85% and 49 to 100% before and after TEE, CT, CMR and 18 F-FDG PET-CT, respectively (P < 0.001 before vs. after). TEE was particularly efficient for atrial masses, especially for the left atrium, with a decision rate rising from 0 to 74% (P < 0.001). 18 F-FDG PET-CT was the most efficient to differentiate benign and malignant etiologies (area under the curve 0.89 ± 0.06 and 0.94 ± 0.05 for benign and malignant, respectively, P < 0.001). A benign or undetermined result on each modality was associated with a good prognosis, compared to malignant. All modalities studied are useful for cardiac mass decision-making. First-line TEE is particularly efficient for atrial masses, whereas CT and CMR are useful for ventricular masses or suspicion of malignancy. A benign or malignant result for each modality is correlated to survival and 18 F-FDG PET-CT is the most effective to define it.