In order to determine whether pulmonic regurgitation (PR) can be reliably diagnosed using contrast echocardiography, we studied 24 subjects using echocardiography during intravenous injections of 5% dextrose solution. Twelve were without PR, and twelve had PR (10 after intracardiac repair of tetralogy of Fallot, one after a Brock procedure for pulmonic stenosis, and one after insertion of a right ventricle-pulmonary artery conduit for pseudo truncus arteriosus). Two blinded independent observers correctly diagnosed PR in all patients when it was present, and correctly excluded it in 11 of 12 of the patients without PR. They disagreed in one patient who had an unusual contrast pattern during diastole. Four postoperative patients had PR by contrast echocardiography despite the absence of a cardiac murmur at the time of their study. We conclude that contrast echocardiography is a safe, simple, sensitive, and specific method for diagnosing PR. Some methodologic suggestions and limitations of the method are discussed.