The rheological properties of soup of tarhana enriched with whey concentrate (WC) at different concentrations (0.0, 6.25, 12.5 and 25.0%) were studied in the temperature ranges of 30, 40, 50, 60, 70 and 80C. Tarhana soup with or without WC behaved as shear thinning. The power law model was determined to be adequate (R2 = 0.900-0.999) to fit the flow curves of tarhana soup with or without WC. Temperature dependency of rheological parameters followed the Arrhenius model (R2 = 0.791-0.965). The mathematical models, power law and exponential functions were developed to determine the apparent viscosity (consistency index, k) of tarhana soup as a function of temperature and added WC. The effectiveness of developed combined models was judged by several statistical parameters In general; exponential function fitted better the effect of WC concentration and combined effect of temperature and added WC than power law function did.