Background: Intravenous leiomyomatosis is a rare, benign, smooth muscle tumor originating in the uterus that may extend through the inferior vena cava into the heart. Intracardiac leiomyomatosis (ICL), present in 10% of patients with intravenous leiomyomatosis, may cause right heart failure, tricuspid valve obstruction, and pulmonary embolism. The imaging characteristics of ICL continue to be reported. The purposes of this study were to characterize the echocardiographic features of ICL and to correlate the clinical findings. Methods: Between 1999 and 2012, 12 female patients with suspected ICL underwent cardiac surgery and histologic confirmation of the tumor. The clinical data, echocardiographic findings, and histologic results were retrospectively reviewed. Results: The ages of the patients with ICL ranged from 40 to 59 years. Ten patients (83%) had undergone myomectomy or hysterectomy, one patient had a uterine fibroid, and one patient had endometriosis. Seven patients (58%) reported dyspnea and/or palpitations, and one patient had syncope; four patients were asymptomatic. Echocardiographic findings included six patients with homogenous right atrial masses, four patients with myxoma-like right atrial masses, and two patients with serpentine, convoluted right atrial masses. In nine patients, the right atrial masses were noted to cross the tricuspid valve. All masses extended from the inferior vena cava. No masses appeared to adhere to the right atrium, right ventricular or pulmonary arterial walls, or tricuspid valve. Tricuspid regurgitation was noted in all patients. No pulmonary emboli were present. Conclusions: The echocardiographic features of the ICL tumors varied. Tricuspid regurgitation and tumors emerging from the inferior vena cava were seen in all patients. Cardiac symptoms, including dyspnea, palpitations, and syncope, occurred in 67% of patients; the remaining 33% were asymptomatic.