Syphilis is a bacterial infection caused by Treponema pallidum and its transmission through blood transfusion poses a considerable risk to transfusion safety. The aim of this study was to assess the prevalence of syphilis among blood donors in Brazzaville, Republic of Congo. This was a cross sectional study conducted from September 2022 to February 2023. Data were collected from the national blood bank in Brazzaville. A structured questionnaire was designed and presented to each donor at the time of sample collection. The demographic data, including age, gender, educational, occupation, marital status and types of donors were routinely collected. During the donation procedure, 5 mL of peripheral blood was collected in a sterile EDTA test tube. All the donor samples were screened by ELISA test. Out of the 2560 blood donors included, 2258 donors (88.2%) were males while 302 (11.8%) were females. The mean age was 32±8.62 years. The overall prevalence of syphilis antibodies was 18 (0.7%). Majority of positive donors were females and in the age group 45-65 years, with a statistically significant correlation (p<0.05). Although, we found a high rate of syphilis carriage among donors in secondary education level, laborer, single and replacement donors, no significant relationship was found (p>0.05). This study provides crucial information on the epidemiology of syphilis among blood donors in Brazzaville and underscores the importance of strengthening screening and prevention strategies among this population.