Control of the preparation of monodisperse particles for green body formation can be achieved by understanding the growth mechanism. Growth processes for colloidal silica and titania were followed by cryo-TEM, which allows direct observation of the particles in the liquid state. Structural development was tracked by quenching samples at successive reaction times. The preparation of silica particles involved the formation of ramified species which subsequently collapsed after reaching a certain size. In the titania system, initially small dense nuclei are observed which eventually form uniformly textured homogeneous particles.