A graded oxidation process, involving UV-ozone (UVO) treatment, was used to create a poly(epsilon-caprolactone) (PCL) surface with a systematic variation in surface chemistry. Time-of-fight secondary ion mass spectrometry (TOF-SIMS) has proved useful in characterizing the chemical composition of these surfaces and in monitoring the oxidation process. The TOF-SIMS data correlates with contact angle data and the results of the binding studies performed with mouse calvarial cells. UVO treatment resulted in a PCL surface with improved wettability and cellular adhesion. (C) 2002 Elsevier Science B.V. All rights reserved.