Modeling the deactivation of heavy oil hydrotreating catalyst was carried out by using a pore plugging model. Experimental data were obtained at constant temperature of 385 degrees C, pressure of 9.8 MPa, LHSV of 0.25 h and 5000 scf H-2/bbl oil. Kinetics was derived from experimental data collected at short times-on-stream (TOS) whereas data affected by pore plugging by metal deposition was obtained between 200 and 2200 h TOS. The model employed was capable of predicting with confidence the profiles of diminution of metal removal (nickel and vanadium) at short and long values of time-on-stream. (C) 2013 Elsevier B.V. All rights reserved.