Multiple regression method provides an easy way of predicting the de pendent variables from the knowledge of many other independent variables. Usually, the physiographic factors of a certain watershed respond dynamic features of stream characteristics and they also play important roles in determining runoff hydrograph at watershed outlet. This research employs geographic information system softwares ARC/INFO and ArcView to obtain watershed physiographic factors followed by the use of multiple regression method to find the design runoff peak flow rate for different return periods. The results show that the design peak rate is highly dependent on the selected watershed physiographic factors. Thus, the proposed method can be used to estimate the peak design flow rate for ungauged watersheds.