We present here the assessment of hazards of natural origin, generated by arrival of tsunami waves to the coastline of the city of Tumaco, located in the state of Nariño, produced by nearby seismic events located in the subduction zone between the Nazca and South American plates and the Panamá fault. Hazards were determined by jointly considering the height and velocity of potentially flooding waves, following a methodology developed by Universidad Nacional de Colombia in 2003, which qualifies the inundation zone not only with the attributes of dry-wet, but also with the potential damage during flooding. Having a detailed knowledge of hazards constitutes by itself the main defense, because in this way there is information on the appropriate use of the land to help decision makers and also it can be used as a tool for disaster mitigation agencies.