Myxomas are the most common types of primary cardiac tumors. Primary cardiac myxomas are typically encountered in the left atrium. Although they are generally benign on histopathological examination, they may cause cerebovascular embolism and mitral valvular obstruction due to their critical location. Myxomas are rarely asymptomatic. Here we report two myxoma cases, a 65 years old male and a 62 years old female, who were admitted to the hospital with rather different clinical presentations. The first patient had only mild dyspnea, whereas the second one presented with symptoms and signs of heart failure besides dyspnea. Albeit not included among the initial differential diagnoses, giant left atrial myxomas were detected in each patient on echocardiographic studies performed during their clinical evaluation. Masses were surgically excised and were pathologically diagnosed as myxomas. We present these two cases in order to underline the fact that although encountered rarely, cardiac myxoma should be included in the differential diagnosis of dyspnea in everyday practice.