Rutting is among the most important distresses in flexible pavements, which is mainly influenced by asphalt mixes properties at high temperatures. There are different methods for measuring the rutting resistance of asphalt mixes. Flow number of asphalt mix, which is measured experimentally by dynamic creep test is one of the most commonly used rutting index, which requires advanced devices, notable cost and time. This paper aims to develop a simple model for predicting the flow number of asphalt mixes using Evolutionary Polynomial Regression (EPR). The developed model can be used for predicting flow number based on Marshall mix design parameters including percentage of fine and coarse aggregates, bitumen content, filler content, air void content, void in mineral aggregate, Marshall stability, and flow. The coefficient of determination (R2) of model in case of training and testing set is 0. 9714, and 0. 969, respectively, which confirms the high accuracy of model. Comparison of the developed model with the existing models shows the superior performance of the developed model. In addition, the parametric analysis indicates the proper conformity of the developed model with the physical behavior of the asphalt mixtures.