A physical model describing the hydrodynamics in a steady-state pressurized cocurrent gas-liquid trickle-bed reactor is presented. The gas-liquid trickle-flow is modeled by an annular pattern in which the gas and liquid phases are separated by a smooth and stable interface. The formulation of the model involves the macroscopic mass and momentum balance equations applied to the gas and liquid phases. The particle-liquid and gas-liquid interactions are evaluated on the basis of the Ergun equation. Comparisons with the experimental data of the pressure gradient and liquid saturation obtained in a large range of operating pressure show that the predictions from this model are more accurate that the ones given from the available correlations. However, it can not be applied to packed beds characterized by a column diameter over the particle diameter ratio D/d(p) of less than 12-14 due to the wall effect.