Right ventricular thrombus in Mycoplasma pneumoniae pneumonia (MPP) patient is rare. Herein we reported 4 cases of right ventricular thrombus. All of them were diagnosed of severe mycoplasma pneumonia, with increased D-dimer. There was no abnormality in the atrial and ventricular diameters with a normal cardiac function during the course of the illness. Every thrombus was closely attached to the tricuspid chordae. Except one thrombus surgically removed, the remaining thrombi dissolved during the follow-ups.