Percutaneous double balloon pulmonary valvotomy was performed on seven consecutive adult patients (mean age 26 years) with congenital pulmonary valve stenosis. The peak systolic transvalvar pressure gradient was significantly reduced from a mean (SD) of 104(30) to 24.3(6) mm Hg. This haemodynamic improvement was maintained at six week follow up. In six patients pulmonary infundibular spasm developed immediately after valvotomy; however, these patients showed considerable haemodynamic improvement at the six week follow up. During balloon inflation the heart rate did not fall below 60 beats/minute and the systemic aortic pressure was maintained above 90 mm Hg. Early results indicate that percutaneous double balloon valvotomy in adults is an effective treatment for isolated pulmonary valve stenosis. Theoretically the two balloons provide a venting area during inflation. This has the advantage of preventing bradycardia or systemic hypotension during prolonged balloon inflation.