Three dimensional collagen/hyaluronan (HA) composite gels are prepared, and their gelation at 32°C and 37°C is studied by rheology and confocal reflectance microscopy (CRM). By varying collagen concentration, gelation temperature and adding HA, we can change the gelation kinetics and manipulate structural and mechanical properties of collagen at equilibrium. We demonstrate that HA can both deposit on collagen fibers as well as remain dispersed throughout the gel. Varying the gelation temperature alters the HA distribution and therefore also varies HA's effects on collagen fibrillogenesis kinetics and equilibrium properties of the gels. CRM and rheology are used complementarily to investigate gelation kinetics. Four dynamic parameters are studied: the arrest time (ta) measured by CRM, the lag phase time (tlag), the slope of the growth phase (kgrowth) and the crossover (gelation) time (tc) determined by rheology. tlag and kgrowth describe the nucleation and growth phases of collagen self-assembly, respectively. They are affected by properties of the dispersing medium and thus by the dispersed HA. tc, which defines the sol-gel transition, is mainly affected by the deposition and viscosity of HA. ta, which describes the arrest of microstructures during gelation, is affected by both dispersed and deposited HA. Together our data indicate that HA can modulate the equilibrium mechanical properties of collagen matrices subtly, but changes the kinetics of their self-assembly and their non-equilibrium structure substantially. This work also shows new ways in which rheology and microscopy can be used complementarily to reveal details of gelation processes.