Seven cases of infective endocarditis (IE) in patients with hypertrophic obstructive cardiomyopathy (HOCM) are presented in this report. The previous literature is critically reviewed, and the following points are discussed: (a) IE complicates HOCM in 5-9% of cases; (b) anatomical and haemodynamic alterations of HOCM cause microtraumas on heart valves and the endocardium; the resulting endocardial lesions represent sites for bacterial seeding as well as other congenital or acquired heart disease; (c) prognosis is worse in patients with IE associated with HOCM than in patients with IE alone or associated with congenital heart disease; (d) the most frequently isolated organisms are saprophytes; (e) most patients were exposed to bacteraemias before the onset of IE.