Collagen molecules form the major part of tissues like bone, cornea or tendon where they organize into ordered fibrillar networks. The acid-soluble protein spontaneously assembles in liquid crystalline phases, characterized in polarized light microscopy and X-ray diffraction. Collagen fibrillogenesis obtained in condensed media establishes a link between the fibrillar networks described in vivo and the mesomorphic states obtained in vitro. Cellematrix interactions on these biomimetic materials are currently analysed with perspectives in tissue engineering. In a morphogenetic context, we propose the hypothesis of a liquid crystalline order, between soluble precursor molecules, preceding fibrillogenesis.