Polysilicone tubing retained 79 to 93% of its original flexibility after radiation grafting with 2-chloroethylacrylate (CEA), quaternization with pyridine, and heparinization. The amount of CEA grafted was linear with time following an induction period. Sample flexibility was studied as a function of CEA addon, pyridine add-on, and heparin add-on. Grafted CEA was found to increase the flexibility of the tubing, thus tending to offset the stiffening effects of the quaternization and heparinization reactions. Tensile moduli and compression load measurements were compared for heparinized and untreated tubing.