After angiography, 6 to 24 hours of bedrest is indicated to assure that adequate hemostasis of the femoral artery has been achieved. Recently, a new hemostatic puncture closure device (HPCD) has been developed, which consists of a resorbable polymer anchor, a resorbable suture, a small collagen plug and an 8Fr delivery device. The device is delivered into the femoral artery through the introducer sheath, the anchor is secured against the intraluminal artery wall, and the collagen plug is deployed on the arterial wall. The prototype of the HPCD was used in 20 patients administered heparin. After insertion of the HPCD, hemostasis was achieved in 1.2 +/- 2.1 minutes; in 2 patients a light pressure dressing was applied for 4 hours to stop oozing. No late bleeding occurred. In 1 patient the positioning suture broke, requiring the application of a pressure bandage. Patients were uneventfully mobilized after 6.7 +/- 3.5 hours. In all patients serial duplex scanning of the femoral artery was performed before and after 1, 7, 30 and 90 days after HPCD placement. In 5 patients a small subcutaneous hematoma close to the site of introduction could be detected by ultrasound 1 day after catheterization. All but 1 patient had normalization of the flow patterns in the femoral artery. It is concluded that: (1) the HPCD is an effective device to achieve immediate hemostasis after arterial catheterization despite antithrombotic therapy, (2) early mobilization was uneventful, (3) duplex ultrasound studies demonstrated only transient changes in the punctured femoral artery, and (4) further investigations are needed to establish the efficacy and safety of the device.