In this paper illustrates how the Volume of Fluid (VOF) model implemented in a commercial CFD code, FLUENT, can be used to track the motion of a fluid-fluid interfaces, in microfluidic devices and capillaries flows in micro-channels. The work presented demonstrates the efficacy of the VOF technique to model multiphase flows at these length scales by modeling 1. The fluid break up at production of droplets at a T-junctions 2. The geometrically mediated breakup of a droplets 3. The rise of a liquid in a capillary. The results in each case are compared with experiments when possible.