Most dam break studies require complex numerical simulations and advanced knowledge in hydraulics. A number of programs are available to perform these simulations and the choice regarding the software to be used must be done within the resources available and the complexity of the problem to be addressed. It remains that this choice is also influenced by the experience and by the knowledge of the analyst. This study reports the simulations results of a comparative study performed for three (3) cases of varying complexity with the software NWS FLDWAV and HEC RAS. Thus, the rupture of a dam in a rectangular channel with uniform characteristics showed that both of the software allows obtaining almost identical results. The other two cases associated with the historical failure of Teton Dam (Idaho, United States) and the combined failure of Drummond and Rock Forest dams (Québec, Canada) showed significant differences in dam breach flow rates and maximum tailwater levels. A comparative analysis of the results leads to recommendations intended for users of these softwares.