The region-of-influence method and regional-regression equations are used to predict flood frequency of unregulated and ungaged rivers and streams of Tennessee. The prediction methods have been developed using strem-gage records from unregulated streams draining basins having 1-30% total impervious area. A computer application automates the calculation of the flood frequencies of the unregulated streams. Average deleted-residual prediction errors for the region-of-influence method are found to be slightly smaller than those for the regional regression methods.