Kinetics of Citronellal conversion to isopulegol over catalyst was performed in a range of temperature 303 - 343 K, a hydrogen pressure 0.62 - 0.20 MPa and a citronelal concentrations at 0.1M to 0.025 M. The results indicate that the catalyst of Iridium supported over SiO2-Nb2O5 induces selectivity towards isopulegol due to high acidity and the presence of surface metal sites. To avoid mass transfer limitations were used a vigorous agitation and small amounts of catalyst (0.05 g). The analysis of rates reaction provided an initial order 1 with respect to concentration and zero order with respect to pressure. Results are explained using a model of complex reactions of the first order.