Immobilized extracellular matrix proteins and neurotrophins have been extensively studied to enhance neuronal adhesion and proliferation on surfaces for applications in nerve tissue engineering and neuroprosthetic devices. This article describes how the coimmobilization of laminin, an extracellular matrix protein and nerve growth factor (NGF), a neurotrophin can enhance neurite outgrowth observed separately with each type of molecule. In the absence of immobilized NGF, PC12 neurite outgrowth is influenced strongly by the presence of NGF in solution and unaffected by significant increases in laminin surface density (18.7-93.5 ng/mm(2)). However, when both laminin and NGF are immobilized together, the surface density of laminin is an important factor in determining whether or not the neurite outgrowth-promoting effect of NGF can be obtained. PC12 neurite outgrowth on surfaces with coimmobilized laminin and NGF with surface densities of 27.6 ng/mm(2) and 1.4 ng/mm(2), respectively, are similar to that observed on surfaces with immobilized laminin and dissolved NGF.