BackgroundAdolescents face significant barriers to access and utilization of sexual and reproductive health services in many low-income settings which in turn may be associated with adverse consequences such as early pregnancy, sexually transmitted infections and unsafe abortion and mortality. There is evidence suggesting that limited access to sexual and reproductive health information and services among adolescents contribute to these outcomes. We aimed to find out the factors that affect the fertility of adolescents aged 15 to 19 years in Zambia and to identify possible drivers of adolescents’ fertility. Methods Secondary analysis of the ZDHS 2013/14 data was carried out to find out the factors that affect the fertility rate of adolescents aged 15 to 19 years using multivariate logistic regression (n=3,666). Results Overall, 23.1% of adolescents had given birth at least once in the five years leading to the survey (n= 3,666, 99.4% response), and 49.8% were rural-based while 50.2% were urban-based. The median number of schooling was 8 years (IQR= 6-10). About 52% of the adolescents were in the poorer, poor and medium wealth quintiles while the other 48% were in the rich and richer quintiles. Factors found to affect fertility include residence, wealth status, educational attainment, marriage and abortion. An urban-based adolescent with a lower socioeconomic status was 2.4 times more likely to give birth compared to rural-based poorer adolescents (95% CI 1.5, 3.7 p<0.001). Although odds of giving birth were much higher among rural married adolescents (aOR 8.0, 95%CI 8.0, 5.4, 11.9 p<0.001) compared to urban married adolescents (aOR 5.5, 95%CI 8.3, 16.0, p<0.001), and these relationship were both statistically significant. Higher educational attainment (aOR 0.7 95% CI 0.6, 0.8 p<0.001) and abortion (aOR 0.3 95% CI 0.1, 0.8 p=0.020) reduced these odds, particularly for rural-based adolescents. Conclusion Despite response aimed at reducing adolescent fertility, low wealth status, low educational attainment and early marriage remain significant drivers of adolescent fertility in Zambia. There is a need to address access to sexual and reproductive health needs of urban adolescents with a lower socioeconomic status.