Introduction – When the population-based surveillance phase of the COVID-19 pandemic began in March 2020, the SurSaUD® syndromic surveillance system (Health Surveillance of Emergency Cases and Deaths) was one of the few systems already in place. This article presents an evaluation of the utility and performance of the SurSaUD® system for monitoring the direct and indirect impacts of the 2020 COVID-19 epidemic through March 2023. Methods – SurSaUD® collects daily, without any a priori selection, individual and pseudonymized data from emergency departments (EDs – Oscour® network), SOS Médecins (SOSM) associations, civil registry offices, and electronic death certificates. The evaluation focused on the system’s flexibility, acceptability, responsiveness, completeness, stability, and utility during the COVID-19 pandemic. Results – The number of patients seeking care for suspected Covid-19 in emergency departments and SOSM, and deaths with Covid-19 listed as a medical cause, evolved in line with indicators from other surveillance systems. The system also made it possible to track indirect impacts related to the pandemic context and to maintain surveillance of all-cause mortality and all emergency department and SOSM visits. Data responsiveness and completeness remained high and stable. System adaptations to account for this emerging situation (new diagnostic codes and indicators) were rapidly implemented. Discussion – To strengthen SurSaUD®’s surveillance capacity, Santé publique France has initiated steps to collect data from SAMU (Emergency Medical Services). This system has once again faced numerous challenges in monitoring the Paris 2024 Olympic and Paralympic Games.