BACKGROUND: Sexually transmitted infection (STI) partner notification is key to fostering STI cure and preventing onward STI transmission; this is critical among people planning for pregnancy given the high STI morbidity and mortality among neonates. This qualitative study explores how women planning for pregnancy and considering HIV pre-exposure prophylaxis approach STI partner notification in Durban, South Africa to inform future interventions. METHODS: We conducted a cohort study evaluating pre-exposure prophylaxis use as a part of safer conception care among adult women (≥ 18 years) without HIV, partnered with a man living with HIV or unknown HIV-serostatus, and planning for pregnancy. As part of an STI-focused sub-study, 25 women who completed etiologic STI screening also completed qualitative interviews exploring participant STI partner notification practices, preferences, and interaction with pregnancy. We used an inductive and deductive approach to generate a codebook, organized our findings according to the Disclosure Processes Model, and identified preliminary themes using content analysis. RESULTS: The median age of sub-study participants was 25 (range 19-33) years, five (20%) were diagnosed with an STI during the study, and 2 (8%) became pregnant during the study. Preliminary themes included 1) Participants' perceptions of their own and their partner's additional partnerships affected STI partner notification perceptions and practices; 2) Participants' asymptomatic presentation and etiologic, laboratory diagnosis supported partner notification; 3) Participants reported male reluctance to engage with healthcare services and a reliance on female participant testing and subsequent partner notification; 4) Participants endorsed provider-assisted STI partner notification; 5) STI diagnoses and partner notification led participants to mistrust their partners and subsequently impacted their condom use during pregnancy planning. CONCLUSIONS: We found a lack of partner concurrency and asymptomatic infection to influence STI partner notification with partner notification affecting pregnancy planning and condom use. Since women report having high STI testing and care engagement, they bear a high burden of partner notification and potential subsequent blame and often appreciated provider assistance. Interventions are needed to engage men in STI testing and care and to mitigate the potential harms of STI partner notification.