Introduction: as Zambia moves towards attaining human immunodeficiency virus (HIV) epidemic control, it is clear significant efforts are required to facilitate achievement of UNAIDS treatment targets by 2030. To accelerate progress towards global target of 95% of people living with HIV (PLHIV) knowing their status, country is promoting community-based HIV testing and same-day antiretroviral therapy (ART) initiation. However, there are uncertainties of how this strategy affects immediate and early engagement in program settings. To address this research gap, we analysed R programme data of PLHIV newly diagnosed and initiated on ART in community and health facility settings. Study objectives were; to estimate the proportion of immediate engagement, to estimate early engagement among newly diagnosed PLHIV and to examine factors independently associated with immediate and early engagement in care among newly diagnosed PLHIV offered same-day ART initiation. Methods: we included all newly diagnosed PLHIV aged 18 years or older and provided same-day ART initiation between October 2018 and January 2019 in Lusaka District. Immediate engagement was estimated as proportion of newly diagnosed PLHIV who visited the health facility at least once within 14 days after same-day ART initiation, whereas early engagement as proportion of newly diagnosed PLHIV active 6 months after same-day ART initiation. Pearson's chi-squared test was used to assess association of outcomes with key background characteristics. Results: of 12,777 newly diagnosed PLHIV who initiated same day ART 7,943 (62%) were tested and initiated in the community. Overall, 6,257 (49%) engaged within 14 days (median 15, IQR: 13-37). Older individuals (36-49 years) were more likely to be engaged at 14 days (aRR 1.29; 95%CI 1.06-1.18; p<0.001) and retained at 6 months (aRR1.27;95%CI 1.21-1.34P<0.001) whilst risk of attrition at 6 months was highest in younger ages (18-24 years) (aRR 0.79;95 %CI 0.76-0.82; p<0.001). Conclusion: to adequately address the HIV epidemic targeted engagement approaches are required particularly in the younger ages.