Rheological behavior of date syrup is an important factor affecting the efficiency of sugar production and refining processes such as boiling, crystallization, separation and pumping. A rotational viscometer was used to characterize the flow behavior of date syrup solution at four different temperatures (20 degrees C, 40 degrees C, 60 degrees C and 80 degrees C) and four concentrations (17, 24,31 and 39 degrees Brix). The samples were subjected to a programmed shear rate increasing from 10 to 100 s(-1) in 2 min, held constant at 100 s(-1) for 10 min and linearly decreasing to 10 during 2 min. The power law model was fitted to shear stress vs. shear rate data to obtain the consistency coefficient (m) and the flow behavior index (n). Both m and n were sensitive to changes in temperature and concentration. The apparent viscosity increases with increasing concentration of date syrup and a decrease in temperature. (c) 2013 Elsevier Ltd. All rights reserved.