Boiling is a phenomenon in which phase change occurs when temperature of liquid in contact with heated surface reaches its saturation temperature corresponding to the ambient pressure. In nucleate pool boiling, the liquid above heated surface is stagnant and bubbles form, grow and depart from the nucleation sites of the surface. Study of bubble dynamics becomes important in pool boiling heat transfer. Present research carries out three-dimensional numerical investigations to study nucleate pool boiling in a rectangular container using commercial software ANSYS Fluent 16.1 having built-in volume of fluid (VOF) multiphase model. In VOF model, volume fractions in each cell are recorded under the constraint that sum of volume fractions of liquid and vapor in each cell becomes unity. User defined function (UDF) has been written to model the vaporization process and is used to calculate mass and energy transfer between the phases during the process. The user-developed subroutines are linked to the main hydrodynamic model equations.