The adsorption behavior of the enzymes creatine phosphokinase (CPK) and glucose 6-phosphate dehydrogenase (G6PDH) on polystyrene, PS, (hydrophobic) and bare silicon wafers (hydrophilic) was studied by means of ellipsometry and contact angle measurements. G6PDH has higher affinity for hydrophobic surfaces than for hydrophilic substrates. The adsorption of G6PDH onto both substrates is a very fast process. The G6PDH coated surfaces presented some hydrophylicity (advancing contact angle, theta(a) < 60degrees) and high hysteresis (Deltatheta = 27degrees +/- 3degrees), indicating surface roughness. The adsorption behavior of CPK onto both substrates presented a continuous increase of the adsorbed amount of CPK as a function of concentration and time. However, CPK showed a higher affinity for Si wafers than for PS films. CPK covered surfaces presented a hydrophobic character (theta(a) > 70degrees), indicating an orientation of its hydrophobic segments to the air, and high hysteresis (Deltatheta = 35degrees +/- 5degrees). The selective and fast adsorption of CPK and G6PDH on the substrates tested is, a promising result to support their application in biotechnological devices.