The thin-layer infrared drying behaviour of wet olive husk (WOH) was experimentally investigated at the temperature range from 80°C to 140°C. The drying rate was found to increase with temperature, hence reducing the total drying time. In particular, as drying temperature was raised from 80°C up to 140°C, the time necessary to reduce the moisture content of the sample from 91.97wt% down to 8.69wt% (dry basis) changed from 105min to 35min.Using a non-linear regression (Marquart's method) and multiple regression analysis, a mathematical model for the thin-layer infrared drying process of WOH was proposed. The values of the diffusivity coefficients at each temperature were obtained using Fick's second law of diffusion. They varied from 5.958×10 −9 m 2 /s to 1.589×10 −8 m 2 /s over the temperature range. The temperature dependence of the effective diffusivity coefficient was described following an Arrhenius-type relationship. Activation energy for the moisture diffusion was determined as 21.30kJ/mol.