Background: Although Zimbabwe has one of the highest rates of modern contraceptive use in sub-Saharan Africa, it also has among the highest prevalence of adolescent pregnancy in east and southern Africa. CHIEDZA is a community-based intervention that integrated HIV and sexual and reproductive health (SRH) services for young people in the context of a cluster randomised controlled trial across three provinces in Zimbabwe (April 2019-March 2022). CHIEDZA provided information and a wide choice of contraceptive methods to young women at its one-stop-shop “youth friendly” venues. This PhD applied the Medical Research Council’s Process Evaluation framework to analyse fidelity,feasibility and quality of the family planning intervention (implementation); the family planning needs and experiences of young women, and how this influenced access to and use of family planning (mechanisms of change); and local factors shaping delivery and uptake of family planning within CHIEDZA (context). As part of understanding implementation and providing context, the routine family planning uptake data from CHIEDZA is presented as background information within the thesis. Methods: The PhD study utilised qualitative (interviews, observations, meeting minutes and field notes) methods between April 2019 and March 2022. The interviews began at the start of the COVID-19 pandemic (April 2020), and therefore methods were adapted to explore adaptations and changes related to COVID-19. A total of 42 interviews with providers implementing CHIEDZA, 49 interviews with young people accessing CHIEDZA, and 18 non-participant observations were conducted. Field notes and meeting notes also captured contextual nuances throughout the intervention implementation phase. Reflexive thematic analysis was iterative, inductive and theory driven. Results: This is a “thesis by publication” consisting of four manuscripts. The first manuscript analyses primary providers’ experiences and perspectives of delivering the family planning intervention including the adaptations and effects on feasibility and quality. The second manuscript examines provider and client experiences of the intervention in light of the COVID-19 pandemic. This paper details how the CHIEDZA intervention functioned before the pandemic, and then tracks the effect of the pandemic on access and use of family planning methods. The third manuscript analyses the family planning needs and experiences of young women living with and without HIV, and demonstrates how integrated family planning interventions support young women living with HIV by acknowledging their SRH needs beyond HIV status and thus can positively contribute to both HIV and family planning outcomes. The fourth and last manuscript then explores young women’s decision-making about family planning use. Conclusion: Process evaluations that purposefully address context may be better equipped to interpret what works or does not work, and is transferrable for family planning intervention for young people. Young women are not a homogenous group. Socio-cultural expectations, physiological changes, and/or the contexts in which they live in can determine how they perceive, access and use family planning services and methods. In addition to engaging with these determinants, public health interventions need to ensure method-mix and competent, youth-friendly providers are available to provide services. Providers’perceptions and values around family planning use by young people, also need to engaged with.