The adhesion of human peripheral lymphocytes (HPL) was studied after preadsorption of fibronectin (FN) and vitronectin (VN) on hydrophilic glass and hydrophobic octadecyl glass. The adhesion of HPL was shown to be dependent not only on the wettability but also on the protein preadsorbed. Vitronectin expressed not only a higher extent of adhesion under static conditions but also a stronger interaction with HPL, indicated by the low detachment under shear stress. The flow experiments also demonstrated that FN adsorbed on octadecyl glass may undergo conformational changes because HPL could be easily removed. Scanning electron microscopy revealed that HPL on both FN- and VN-coated glass spread well whereas particularly on FN-coated octadecyl glass less cell spreading was observed; moreover, some round cells were detected. The typing of adherent HPL by immunofluorescence microscopy showed that on FN- and VN-coated glass about 70% of all HPL were T-cells (CD 3+). However, on octadecyl glass, particularly on VN, a smaller percentage of CD 3+ cell was observed. The testing for the beta 1 integrin--the receptor for FN and the alpha v integrin--the receptor for VN demonstrated that about 70% of all cells on FN-coated glass were positive for the beta 1 integrin. On VN-coated glass, however, only 5% of HPL were positive for the beta 1 integrin. Although on VN a high adhesion and strong binding of HPL was observed, no presence of the alpha v integrin was detected.