Recently, interest in olive leaves has increased because of their high phenolic contents. Although the critical process in olive leaf treatment is drying, the drying behavior of olive leaves has not been known yet in the literature. In this study, olive leaves were dried in a tray drier at the temperature range of 50-70C and velocity range of 0.5-1.5 m/s. Eleven different semitheoretical thin-layer drying curve models were used to characterize the drying behavior of olive leaves. Effects of drying air temperature and velocity on model coefficients were determined by multiple regression analysis. The correlation coefficient (r), the reduced chi square (chi 2) and the root mean square error (RMSE) were taken as the statistical criteria parameters for model comparisons. It was found that the modified Henderson and Pabis model represented drying characteristics best with r = 0.9955. Effective diffusivity was computed by taking account of temperature and air velocity. The temperature- and velocity-temperature-dependent activation energies were 60.97 +/- 3.21 and 75.98 kJ/mol, respectively. It was concluded that olive leaves could be dried successfully by thin-layer drying procedure, and the drying rate was influenced mainly by drying air temperature.