Outbreaks of healthcare-associated infections (HAI) are relevant causes of morbidity and mortality. Healthcare-authorities should monitor them to allow prompt interventions, identify tendencies along the time, and develop large scale strategies to avoid new cases and clusters. According to the Brazilian legislation, any outbreak should be reported to health authorities. Sao Paulo State Health Department (Brazil) has a system in place since 2011 to monitor HAI outbreaks. This study aims at describing the 3.5 last year’s results of surveillance system for monitoring HAI outbreaks. Methods:Study design: Quantitative descriptive study. Source of information: Database from HAI outbreak reports, Division of Hospital Infection at Sao Paulo State Health Department. Reports were filled out online by professionals from healthcare settings or regional health authorities according to predefined criteria. Interventions were put in place by the health authorities based on the analysis of each situation in a timely manner. Variables analyzed: Number of reports, local, infection site, type of care unit, causative microorganisms, number of cases, and number of deaths. Results: The number of reports have been stable for 3 years: 2016 (n = 34, 34.7%), 2017 (n = 28, 28.6%), 2018 (n = 25, 25.5%) and the first semester of 2019 (n = 11, 11.2%). These reports encompassed 712 confirmed cases and 123 deaths. The reports were mainly about infection outbreaks; 6 reports were about colonization of multidrug-resistant microorganisms. The bloodstream was the most frequent infection site in the HAI outbreak reports (n = 37, 37.7%), followed by respiratory tract (n = 25, 25.5%), urinary tract (n = 10, 10.2%), and surgical wound (n = 9, 9.2%). HAI outbreaks happened more frequently in intensive care units, including neonatal, pediatric, and adult ICUs (n = 38, 38.8%), followed by clinical and general wards (n = 20, 20.4%), hemodialysis (n = 6, 6.1%), and surgical wards (n = 5, 5.1%). Among reported outbreaks, 62.2% occurred in the capital and the metropolitan region of São Paulo. Microorganisms causing the HAI outbreaks reports were mainly carbapenem resistant, both Klebsiella pneumoniae (n = 28, 28.5%) and Acinetobacter baumannii (n = 12, 12.2%), but carbapenem-susceptible Pseudomonas aeruginosa (n = 7, 7.1%) was also reported. Conclusions: HAI outbreaks reported to health authorities in Sao Paulo may represent only a minute percentage of the total outbreaks, most of which are still not being reported, despite the normative. However, the available data emphasize the importance of developing strategies for intensive care units and hemodialysis units that focus on reducing bloodstream infections caused by multidrug-resistant gram-negative organisms.