Thermophysical properties of yacon (Smallanthus sonchifolius) - specific mass, specific heat and thermal conductivity were obtained experimentally at 30 min intervals in order to model and simulate the mass and heat transfer phenomena involved in a drying process. Thermal diffusivity was calculated using the former properties. Empirical models obtained by nonlinear regression were successfully fitted to the thermophysical properties rates. Using the data of thermophysical properties in function of moisture content, the theoretical drying model was simulated and validated by the experimental results of yacon's moisture content and temperature, providing determination coefficients higher than 0.97. (C) 2013 Elsevier Ltd. All rights reserved.