Introduction: The HIV/AIDS scourge remains a major public health threat in South Sudan particularly to the unborn children due to vertical transmission. Objective: This study aimed to assess the prevalence of HIV among pregnant mothers receiving antenatal care (ANC) services at Kator Primary Healthcare Centre in Juba. Method: The study used a cross-sectional design in which systematically selected ANC records of January to June 2021 were collected and analyzed using SPSS Version 16.0. Fisher’s exact values were obtained to test for significance. Results: The HIV prevalence rate among pregnant mothers receiving ANC services at Kator PHCC was 2.25%. The modal age group was 21-25 years. HIV prevalence was highest among mothers who attained primary education or less, urban dwellers and married mothers in their 3rd trimester of pregnancy. Conclusion: HIV prevalence among pregnant mothers receiving ANC services at Kator PHCC in Juba is comparable to the national average.