The unusual congenital anomaly, double chambered right ventricle due to aberrant muscle band with intact ventricular septum in 10 years old female patient is presented. The pressure gradient is 70mmHg between inflow tract and outflow tract of right ventricle and the aberrant muscle band is 2X4.5cm arising below the infundibulum and traverses the right ventricular cavity, extending from its anterior wall to the crista supraventricularis forming broad triangular base in parietal anterior wall. By resecting out this muscle band clearly, the outflow tract obstruction is completely relieved.[KTCS 1978;1:65-68]