In this work the effective molecular diffusion in homogeneous porous media was studied. An experimental setup was constructed to measure the effective molecular diffusion coefficient in packed unconsolidated sands, which allowed to take samples of fluids at different positions and times. The fluid samples were analyzed by gas chromatography to determine fluid concentration; these data were analyzed using the Fick’s second law to calculate the molecular diffusion coefficient. These results were compared with those obtained using a different methodology based in pressure changes developed by Luna et al. A good agreement between both methodologies was obtained.