We report our recent experience of 207 consecutive transeptal catheterizations performed in the following groups of patients: aortic valve disease in 152, mitral valve disease in 20, combined aortic and mitral valve disease in 11, hypertrophic obstructive cardiomyopathy in 11, assessment of prosthetic cardiac valves in nine, and four miscellaneous. Transeptal catheterization failed in 20 patients. There was no attempt to advance the transeptal catheter from the left atrium into the left ventricle in 18 patients, and failure to advance the transeptal catheter from the left atrium into the left ventricle occurred in 13 patients. Transeptal catheterization was achieved in a mean time of 9.7 +/- 4.6 SD min. There were no deaths, two major and four minor complications. We conclude that transeptal catheterization remains a useful technique that in experienced hands is both rapid and safe.