Pressure drop and liquid saturation in a cold model representative of trickle-bed reactors operating in the high interaction regime were measured using air and water at atmospheric pressure. Five different packing similar in shape and dimension to typica1 industrial catalysts (cylindrical pellets, raschig rings, extrudates) were tested, covering a wide range of geometric characteristics. The adequacy of the most recent literature correlations for pressure drop in trickle-bed reactors was checked. The best predictions are provided by an empirical correlation based on the Lockhart-Martinelli parameters. A new model of similar accuracy was derived, which provides a theoretical basis for the successful application of the Lockhart-Martinelli approach.