First part of the article describes calculation procedure for theoretical flood waves in gauged catchments using the Cracow University of Technology method and Warsaw University of Technology method. Both methods are based on unified unit hydrograph (UHG). Second part presents cross evaluation of mentioned methods on in relation to records historical flood waves. Evaluation was performed on 8 different catchments in Upper Vistula Basin. Selected catchments represented small to big areas with mountainous, highlands and lowlands characteristics. The Cracow University of Technology method of theoretical flood waves determination gives more reliable result.