Eleven patients whose ECG and VCG showed a left bundle branch block with right axial deviation (between + 90 degrees and + 150 degrees) were studied with clinical and radiological investigations. All of them had pathological abnormalities of cardiopulmonary apparatus and cardiac enlargement, but only one had congestive heart failure. The right axial deviation was due in one case to the vertical position of the heart in the chest and in three cases to conduction defects of the cardiac impulse through the left bundle branch. In the remaining cases the right axial deviation was dubious. The authors present and discuss all possible factors which could cause such deviation of QRS axis in the left bundle branch block.