Infiltration is a fundamental component of the rainfall-runoff process. It was characterized through the adjustment and comparison of the Smith-Parlange, Green-Amptd, Philip, Horton and Kostiakov equations, using simulated rain in poorly developed soils from three geological formations and from different ages (Marino Fm., Mogotes Fm., quaternary cover). Trials with the rainfall simulator were run in piedmont areas west of the city of Mendoza. Adjustments were performed separately for each of the trials and globally for each surface cover. The adjustment was satisfactory when the observed and the simulated infiltration velocity curves were compared using lumped parameters. The Green-Amptd model exhibited the best behavior for the three covers, while the Smith-Parlange equation was the least accurate, al- though it had little dispersion in the prediction errors. The Kostiakov and Horton equations yielded satisfactory results in view of the fact that the development of the infiltration rate curve was simulated after the impoundment time was determined with the Green-Amptd formula. The Philip model is not consistent, with the exception of the results obtained for the Marino cover. In the post-calibration procedure the parameters showed no noticeable differences with respect to those obtained during calibration. In every case the relative squared error of the infiltration curve was very satisfactory, below 5%.