A device for delivery of an embolization plug (15) into a biological vessel includes a tubular sheath (22) assembly and a flexible catheter (30) disposed therethrough. The catheter has a front end section (32) which is semicircularly arcuate when unconstrained and holds an embolization plug (15) near its front opening. The catheter can be rotated inside a vessel from its back end and the curvature of the arcuate front end section can be varied as the distance by which it extends from the sheath assembly is adjusted. The plug is pushed forward out of the catheter by a push rod (50) which is disposed in the lumen of the catheter and has a flexible front part which can move through the catheter without significantly affecting the arcuate configuration of its front tip section.
