Background: The Zambia Demographic Health survey conducted in 2014 reported a notable number of adolescent girls 3627(11.7%) who had their first sexual intercourse by age 15 and the Zambia National Health Strategic Plan 2017-2021 highlighted the high adolescent birth rate which stood at 141 per 1000 live births between the years 2013 and 2014. In this paper, we adopted the WHO definition of an Adolescent as any person between the ages of 10 to 19 years. This study aimed at investigating baseline factors that leads to agreeing into early childbearing practices among adolescent girls in selected rural districts of Zambia nested in the RISE cluster randomized trial. In this study early childbearing was taken to mean any pregnancy before the age of 16. Methods: This study is a nested quantitative cross-sectional design. Participants were girls attending grade seven at various schools in 2016. Information on factors that could influence the participants' view on childbearing were collected at baseline. A complete enumeration of approximately 5000 girls recruited in 12 rural districts of Central and Southern provinces were analysed. Descriptive statistics were presented as frequencies and percentages in tables.To check for association with categorical variables, either Chi-squared or Fisher's exact test was done depending on whether the assumptions for Chi-squared test were satisfied or not. Univariate and Multiple Logistic regression analysis was used to test the association between independent factors and early childbearing. Clustering in the study was accounted for using robust standard errors. Results: The findings showed that more than two-thirds 3189 (73.7%) of the participants had little or no knowledge regarding adolescent sexual and reproductive health services while less than one-third 1137 (26%) had knowledge regarding Adolescent Sexual and Reproductive Health services. Adolescents with mobile phones were 2.5 times more likely to have children early compared to adolescents without mobile phones. Majority 227 (69%) who agreed to early childbearing were aged 10 to 15 years, whilst the least 99(30.3%) were in the age range of 16 to 20 years. In addition, results revealed that one-year increase in age of an adolescent girl increases agreeing to early childbearing by 30% (OR=1.30, 95% CI (1.01, 1.67), p-value=0.03). Overall, very few factors (mobile phone and age) at baseline were found to be associated with agreeing to early childbearing. Conclusions: Only mobile phone use and age were associated with agreeing to early childbearing.