We are reporting a case of a 80-year-old lady with effort angina who underwent coronary angiography through the right radial artery, using a dedicated radial multipurpose 5 French Optitorque Tiger catheter. The catheter was advanced into the left ventricle and a left ventriculogram was obtained, while the catheter appeared optimally placed at the centre of the ventricle and the pressure waveform was normal. A large posterior interventricular vein draining into the right atrium was opacified, presumably because the catheter’s end hole inadvertently cannulated an endocardial opening of a small thebesian vein, with subsequent retrograde filling of the epicardial vein. Our case suggests that caution is needed when a dedicated radial catheter with both an end-hole and a side hole is used for a ventriculogram, as a normal left ventricular pressure waveform does not exclude malposition of the end-hole against the ventricular wall. We are reporting a case of a 80-year-old lady with effort angina who underwent coronary angiography through the right radial artery, using a dedicated radial multipurpose 5 French Optitorque Tiger catheter. The catheter was advanced into the left ventricle and left ventriculogram was A large posterior interventricular vein draining into the right atrium was opacified, presumably because the catheter’s end hole in advertently cannulated an endocardial opening of a small thebesian vein , with subsequent retrograde filling of the epicardial vein. Our case suggests that caution is needed when a dedicated radial catheter with both an end-hole and a side hole is used for a ventriculogram, as a normal left ventricular pressure waveform does not exclude malposition of the end-hole against the ventricular wall.