The objective of this research was to determine by means of a computational model the degree and area of ​​affectation implied by the release of a toxic ammonia cloud from a 1000 Kg storage tank. The SCRI-Fire simulator of the company Dinámica was used. Heuristics feeding it with meteorological data from the city of Los Mochis, Sinaloa, physicochemical properties of ammonia and characteristics of the tank. The simulation was carried out in the summer and winter scenarios. As results of the simulation, in case of an ammonia leak, at a distance of 1038.67 meters there would be a concentration of 2500 ppm, which could produce the obstruction of the airways in people and at a distance of 818 meters there would be 5,500 ppm of ammonia, which is fatal to people for an exposure time of 30 minutes. Good management of dangerous substances such as ammonia is necessary, to avoid damage to the health of exposed people and negative effects to the environment, constant training of personnel who handle this dangerous substance is required, and that companies that handle ammonia are They are far from residential areas, and places with a lot of people.