The purpose of this study was to assess 4 Fr Judkins catheters with modified shorter tips for performing selective coronary angiography in infants and young children. Twenty patients ranging 6 weeks to 3. 8 years of age were enrolled. Retrograde left heart catheterization and selective coronary angiography were performed. Right (JR) and left (JL) catheters with modified 1.5- and 2.5-cm curves (Cordis) were used. Thirty-six of 37 coronary arteries were successfully cannulated and demonstrated. Median procedure time was 95 sec for the right and 50 sec for the left coronary artery. Median fluoroscopy time was 1.1 min for the right and 0.7 min for the left coronary artery. The JL 1.5 appeared best suited for patients less than 75 cm tall. The JR 1.5 was suitable for patients up to 85 cm tall. Taller patients required the 2.5-cm curves. It is concluded that these modified 4 Fr Judkins catheters were effective.