A model was developed to describe the kinetics of protein and platelet deposition and embolization on biomaterials. The model assumes that proteins can be adequately represented by fibrinogen, albumin, and Factor XII, that protein adsorption is Langmuir-type, that surfaces are homogeneous, and that all adsorption and deposition steps are first order. Eleven model parameters were determined from literature experimental data from ex vivo experiments utilizing canine and baboon blood on Silastic, one parameter came from adsorption of Factor XII on glass, and three parameters were obtained by minimizing differences between experimental and predicted fibrinogen adsorption, and platelet deposition and embolization behavior. The model well predicted observed behavior for fibrinogen adsorption, platelet deposition, and platelet embolization on Silastic, and platelet embolization from both polyacrylamide and HEMA-MAAC.