We prepared amyloid-like fibrinogen (Fg) fibrils at pH 2.0 in the absence of thrombin; furthermore, we prepared uniform 2-D Fg fibril networks on a hydrophilic mica matrix. We found that several experimental parameters, such as concentration, pH value, and ionic strength, strongly affected the formation of Fg fibrils as well as fibril networks. Biomimetic mineralization was conducted on the Fg fibrils and 2-D Fg fibril networks in 1.5x simulated body fluid (SBF) for different periods of time. The present results may lead to a fundamental understanding of possible mechanisms for the pH-mediated self assembly of Fg molecules and the formation of Fg fibrils and fibril networks in the absence of thrombin and provide a feasible strategy that may enable the design and fabrication of new functional biomaterials based on self-assembled protein fibrils.