Objective: The aim of this study is to investigate the previous four months (March-July 2020) SARS-CoV-2 infection rate, seroprevalence and the variables affecting these in HCWs in a university hospital. Methods: The present study is a SARS-CoV-2 seroprevalence study on HCWs working in a tertiary hospital during the first stage (March-July 2020) of the outbreak in Turkey. The presence of IgM and IgG antibodies against the spike structure of the virus was investigated by the chemiluminescent enzyme immunoassay (CLIA) method using the commercial antibody kit (COV2T, Siemens®, Tarrytown, NY, US). Participants’ socio-demographic characteristics, health status, lifestyle, risky occupational and social and personal protective equipment (PPE) usage were independent variables of the study. Chi-square test and Fisher’s exact test were used in univariate analyzes, and accepted type 1 error value was 0.05. The analyzes were made using the SPSS 23.0 package program. Results: 1177 out of a total of 1702 health workers participated in the study. Participation rate was 69.1% . The mean age of the study group was 35.3 ± 9.8 and 62.7% were females. SARS-CoV-2 infection rate detected by nucleic acid amplification test (NAAT-PCR) or antibody test (Elisa) was (18/1177) 1.5%; The seroprevalence of SARS-CoV-2 was 1.01%. 17% of the entire SARS-CoV-2 cases were asymptomatic. The highest infection prevalence was significantly higher in auxiliary health workers (3.7%) compared to other groups. The presence of symptoms HCW’s and their family members that did not exist before in the last 15 days, being overweight or obese and consulting as contacted person in survelliance unit were significantly related to having SARS-CoV-2 infection (p