The rheological behaviors of pekmez samples (mulberry, grape, rosehip and harnup juice) were investigated. Viscosity was measured at 5, 10, 15, 20 and 30°C using a rotational viscometer in the shear rate range of 0–93s −1 . An emprical power-law model was used to describe the rheological behaviors of pekmez samples. Pekmez samples were found to exhibit non-Newtonian behaviors. An Arrhenius equation was used to determine the effect of temperature on viscosities of pekmez samples and thus E a values of pekmez samples were calculated. The activation energies vary from 18.509 to 74.658kJ/mol depending on the solid contents (39.44, 60.48, 67.08, 69.68, 71.98, 74.22, 75.4 and 75.46°Brix).