Collagen is the most abundant structural protein in mammals. It is found in various tissues such as bone, teeth, tendon, cartilage, and skin. Collagen aggregates are observed in vitro and in vivo, and are found to be morphologically identical. Our study is focused on understanding the fundamental mechanisms in which type I collagen monomers self-assemble in vitro into highly ordered aggregates. By varying assembly conditions such as ionic strength and collagen concentration, collagen self-assembly could be controlled to grow into various forms of aggregates. For instance, very low concentrations of collagen compared to methods in previous studies yield the novel type of collagen intermediate aggregate that is helical in nature but lacking in the characteristic ~67 nm banding periodicity. Understanding the assembly parameters for such helical collagen intermediates may hold the key to further insight into mature helical fibrils found in vivo and in vitro.