Background: Sexually Transmitted Infections (STIs) are a public health concern worldwide. Awareness campaigns have been conducted worldwide, educating communities on their manifestations, prevention, and steps to be taken once infected. Objective: This study aimed to determine childbearing women’s knowledge, attitudes, and beliefs about STIs. Methods: A cross-sectional study was conducted at a district hospital near Pretoria in South Africa. The population comprised 190 childbearing women registered at the family planning clinic of the hospital. The sample size of 130 participants was computed at a confidence level of 95% with an error margin of 5%. Participants were selected using a table of random numbers, and data collection by means of a researcher-administered questionnaire. The SPSS software (version 22) was used for data analysis. Statistical significance was set at p < 0.05. Results: Of the 130 participants, 123(94.6%) knew that STIs can be acquired through sex, and 41(31.5%) did not know that STIs can be asymptomatic. The most known STI was HIV by 117(90%) participants, the most known transmission route was sexual intercourse by 126 (96.9%) participants, and the most known symptom was penile/vaginal discharge by 108(83%) participants. Seventy-four (57.3%) regarded STIs as not dangerous, based on their belief that STIs are curable. There was generally a poor association between knowledge on STIs and alcohol consumption (p > 0.05). Conclusion: The childbearing age women knew most aspects of STIs, but had gaps of knowledge. They believed that STIs are curable, which influenced their attitudes towards STIs. Health care professionals are challenged to educate patients on STIs on an ongoing basis.