ABSTRACTOBJECTIVETo estimate the prevalence of exposure to the SARS-CoV-2 virus among individuals living in restricted freedom.METHODSA seroprevalence survey was carried out with the population of the female penitentiary of the Centro de Progressão Penitenciária (CPP) in Butantan (municipality of São Paulo), between June 24 and August 20, 2020. During this period, according to the Secretariat of Penitentiary Administration (SAP), the positivity of rapid tests among inmates ranged from 65% to 78%. The evaluation method used in the study was the “One Step COVID-19” rapid test (chromatography), from the company Wondfo, also using the RT-PCR method in symptomatic participants to confirm the viral condition. The study population consisted of 879 female inmates and 170 employees of the institution.RESULTSThe prevalence of total antibodies (IgG/IgM) against the SARS-CoV-2 virus in the total population of 1049 study participants was 6.1%; among the population of 879 inmates,a prevalence of 5.8% was observed, and among the institution’s employees, 7.5%.CONCLUSIONSThe prevalence of covid-19 at the Butantan CPP was low, which is due to the implementation of simple prevention measures at the institution, such as the use of masks (with appropriate changes), emphasis on hygiene, hand washing and social distancing, in addition to other strategies, such as suspending inmates’ visits from relatives and friends and cutting back on elective medical appointments and outside work.