Objective: Describe the knowledge and practices regarding dengue prevention measures among the residents of a Peruvian city affected by a dengue epidemic following the 2018 Coastal Child, and compare the knowledge using the ENAPRES 2016 questionnaire. Methods: A descriptive cross-sectional study was conducted in which information was collected by means of two consecutive questionnaires. The sample was obtained with a 95 % confidence interval, a 29.1 % expected proportion, 4.5 % precision and a population of 8 210 households, and considering losses will be a sample of 380. Results: The population was predominantly female (73.7 %), with a mean age of 42.5 years, 41.8 % complete secondary schooling, and 54.5 % housewives. The source of information most commonly used was the health center (48.7 %). 21.1 % reported knowing about the disease, 75 % knew that it was transmitted by mosquitoes, and 86.1 % knew that mosquitoes reproduce in stagnant water. In addition, 69.2 % recognized the symptoms of the disease. 9.7 % referred to measures to eliminate breeding sites, and 20.5 % to measures to avoid being bitten. 83.2 % stated they knew about temefos and its use. The symptoms most commonly identified by the population were fever, headache, bone and/or joint pain, and muscle pain. According to the comparison made with the ENAPRES 2016 questionnaire, there was an increase in knowledge about alarm signs (bleeding, nausea and vomiting). Conclusions: Knowledge about dengue prevention was scarce and the practices observed among the population of Tuman were insufficient, but improvement was observed in the knowledge about some prevention measures with respect to 2016.