Left ventricular outflow tract obstruction may be caused by abnormalities of the various structures comprised by the outflow tract. Hypertrophic cardiomyopathy is one of the more common causes, but many are rare anomalies, a collection of which we have compiled. We present a case of left ventricular outflow tract obstruction mimicking aortic stenosis in an adult. This was found to be due to abnormal insertion of a hypertrophied papillary muscle, successfully corrected by mitral valve replacement.