Intravascular ultrasound, performed using a 0.018 in guide wire with a 30 MHz ultrasound transducer, allows to study the acute recoil of Palmaz-Schatz stent. This case showed that the acute recoil of the Palmaz-Schatz stent occurs immediately after stent implantation. The analysis of diameter and lumen cross-sectional area at the stent site was performed at different levels of dilatation. A 20% reduction of cross-sectional area was found immediately after stent expansion and balloon deflation.