Hydrologic response indices have frequently been employed in contemporary regionalization research related to predictions in ungauged basins. The present study focused on estimation of runoff coefficient for ungauged catchments in the Lake Tana basin using regionalization methods. of approach and developed regionalization models using multiple linear regression to derive relationships between hydrologic response and catchment physical characteristics for 9 gauged catchments in the Lake Tana basin. We developed regionalization models using multiple linear regression to derive relationships between hydrologic response and watershed physical characteristics for nine catchments in the Lake Tana basin from 1992-2014. The model provide an empirical means for simulating runoff in ungauged basins at a monthly time step without implementation of a rainfall-runoff model. For the dependent variable in the regression model, we used monthly discharge as the indicator of hydrologic response and defined it using the mean of these monthly discharge for each watershed as a representative observation. Models using mean observations for the dependent variable generally simulated monthly runoff with reasonable skill in the validation watersheds (Nash-Sutcliffe efficiency of greater than 0.5, R2 greater than 0.6, and relative runoff volume of less than ±10%) for each catchments. These results suggest the viability of empirical approaches to simulate runoff in ungauged basins.