Abstract : Dengue fever is a disease transmitted through mosquitoes. In Cuba the transmission vector is the Aedes Aegipty mosquito. Dengue fever is endemic in many areas in Central America and the Caribbean, but in Cuba it is always an imported disease, it is not endemic. One of the problems confronted by the Health System is finding the size of the mosquito population during an outbreak of dengue fever. There are indices studied by the surveillance system, and there are indicators that point to a possible outbreak, if a case is introduced by some traveler that is unaware of its condition as a carrier of one of the dengue viruses. Since the first papers (Esteva and Vargas, J. Math Biol, 1999) modeling dengue fever has been a priority in the countries where it is endemic.In our work using a mathematical model with ODE adapted from (Coutinho and all, Bull. Math. Biol, 2006), we fit the epidemic curve given by the model to the known cases of a dengue fever outbreak in the city of Havana, using as parameters the carrying capacity for mosquito eggs, larvae and pupa. This carrying capacity depends on the actions the Health System takes to eliminate areas where the mosquito can breed. Once we have the parameters that fit the part of the full blown outbreak, we use these values to estimate the efficiency of the system in eliminating the mosquito and its breeding grounds. We present these results using the same epidemic outbreak in the city of Havana.