Isolated pulmonary stenosis, a relatively common congenital anomaly that accounts for about 10 percent of all congenital heart disease, is characterized by stenosis of pulmonary valve itself, infundibulum or both of them. Since cardiac catherterization was applied to man by Cournand and Ranges, pulmonary stenosis had been easily diagnosed and many clinical studies had been investigated. It has a wide clinical spectrum depending on the degree of stenosis. The electrocardiogram, phonocardiogram and chest X-ray have proved useful in estimating the severity of hemodynamic facotrs in individual cases. This series comprises 47 cases in whom the clinical diagnosis of isolated pulmonary stenosis was confirmed by right heart catheterization with cardiac cineangiography at Severance Hospital, Yonsei University. An attempt was made to correlate the electrocardiographic, phonocardiographic, chest X-ray findings, and types of stenosis with the hemodynamic data in these cases. 1. Of 47 patients, 33 were male and 14 female. Their ages ranged from 2 to 42 years: the mean age was 19.1 years. 2. The incidence was 5.9 percent of all 797 catheterized congenital heart disease cases. The pulmonary valvular stenosis was 30 (68.3%), infundibular 7 (14.6%) and combined 10 (21.6%) cases. 3. The correlation between electrocardiogram and hemodynamic data were as follows. i) The regression equation between right ventricular sysytolic pressure (RVSP) and height of R wave in V1 lead (RV1) was RVSP=3.32 RV1+48.2: its correlation coefficient was 0.818 and it was very significant (p=0.000). ii) The higher the RVSP, the more the frontal axis of QRS complex shifted to the right side (r=0.55. p=0.001). iii) The RVSP of the groups with positive ECG findings such as p-pulmonale, right ventricular hypertrophy or right ventricular strain were much higher than the RVSP of the groups without such findings (p=0.032.0.000, 0.000). iv) The group with RV1 higher than 20 mm showed much more elevated mean of RVSP than the group with lower RV1 (p=0.000). v) The groups with the above mentioned positive ECG findings showed good correlation with the severity of RVSP which was arbitrarily classified as 49 or less, 50~100, and 100 mmHg or more (chi-square=8.96, 26.69, 19.06; p=0.011, 0.000, 0.000). 4. The group with late occurrence of the maximum intensity of the ejection systolic murmur showed higher mean of RVSP than the group with early peak of the murmur (p=0.014). 5. The means of RVSP of the groups with chest X-ray findings such as decreased pulmonary vascularity, were much higher than the means of RVSP of the groups without such findings (p=0.000, 0.005, 0.015). The groups with above mentioned positive chest X-ray findings showed good corelations with the severity of RVSP which was classified as above limits (chi-square=7.55, 10.94, 13.36; p=0.022, 0.004, 0.001). 6. Combined pulmonary valvular and infundibular stenosis showed more severe systolic pressure gradient and higher mean of RVSP than the isolated types (p=0.000).