Background: Risky sexual behaviors contribute to increased risk of adolescent pregnancy and HIV infections. This qualitative study sought to understand factors that might buffer this risk amongst sexually-active adolescents in Soweto, South Africa.Methods: We used purposive sampling to recruit women at age 24 years from Soweto, South Africa, who self-reported having sexual debut by age 15 years. Twenty women were recruited into 2 equal groups: (i) those who did not become pregnant before 18 years (n=10) and (ii) those who became pregnant before 18 years (n=10). In-depth qualitative interviews were conducted with the two groups of women to understand their family backgrounds, the conversations about sex to which they are exposed, sexual behaviors and steps they took, or didn’t take, during adolescence to prevent early pregnancies. Interviews were transcribed verbatim and thematically analyzed with the aid of MAXQDA software.Results: Both groups of adolescents reported predisposing risks to early pregnancy including influence from peers and older friends to engage in early sex; unstable family relationships and limited conversations about sex. Key factors that differentiated the two groups were family structure and support, as well as, the adolescent’s ability to navigate choices and make decisions on consistent condom use, access to information and desire to complete schooling. Other supportive systems identified by those who did not become pregnant included life-orientation courses provided at school, access to health services, and positive peer influences. Conclusion: The family is a key institution in supporting adolescents’ decisions regarding their behaviors and choices, as are peers and exposures to formal or informal information they receive about sex. Policy makers should work closely with other social support systems such as schools, healthcare providers and peers to ensure that adolescents have access to relevant information, including sex education, and contraceptives.