While the introduction of antiretroviral therapy has led to significant improvements in the survival of children living with HIV, several factors hamper its ultimate success in resource-limited settings. These factors include lack of proper management of the child’s treatment and follow-ups due to the existing fragile health and social systems and psychosocial and economic strains of family caregivers. The overall aim of this thesis was to contribute to the improvement of care for children living with HIV on antiretroviral therapy in Ethiopia through enhanced knowledge and understanding of the family caregivers’ experience and factors of importance for the children’s outcomes. The knowledge will serve as a basis for further planning of care and informed decision making in the area. A mixed method design study including both qualitative and quantitative methods was carried out. Two studies described in four interrelated papers were derived from a cohort of children less than 14 years of age prospectively enrolled to ART and their respective family caregivers. Qualitative interviews using a hermeneutic phenomenology approach illuminated the caregivers’ lived experiences from the child’s diagnoses and over two years. Quantitative methods were used to describe caregiver-reported ART non-adherence and its predictors among children in the early stages of treatment and to determine rates and predictors of mortality and lost to follow-up among children on ART.In the qualitative study, in-depth interviews were conducted among family caregivers at two different time points, when the child was enrolled in ART, Paper I (n=21) and two years after, Paper III (n=18). A prospective cohort study was conducted to evaluate ART non-adherence and its predictors in the early stages of treatment, Paper II (n=306)) and to examine the association between predictors and times to attrition among children, Paper IV (n=304).The result showed that at the beginning of the child’s enrollment in ART the caregivers’ lived experience was described as surviving overwhelming challenges. They felt overwhelmed due to the caring burdens and felt uncomfortable about their child’s HIV and treatment status. However, their commitment to caring for their child, their belief in God and treatment and the support from health workers empowered and helped them to survive their challenges. As the years went on, caregivers felt relieved from their burden of caring after their child’s health restored due to the treatment and support given by the health facilities. The caregivers experienced regained normality in their life and they felt hope even if they faced challenges in terms of stigma in the community and dealing with conflicts especially when they had not revealed the diagnosis to their child.Children whose caregivers were not undergoing HIV treatment and care themselves were less likely to be non-adherent during the first week of treatment and the children whose caregivers did not use a medication reminder after one month of treatment initiation were more likely to miss the prescribed dose. One month after the treatment initiation, those receiving protease inhibitor (LPV/r) or ABC-based treatment regimens were more likely to be non-adherent. At 12 months of follow-up, 24 attritions were recorded, yielding an attrition rate of 8.3 per 100 PYO. Six children were reported to be dead, leading to a mortality rate of 2.1 per 100 PYO, and five were transferred to another facility. Child age below three years and baseline Hgb in g/dl <10 g/dl had the higher risk of attrition. Baseline Hgb in g/d <10 g/dl and WHO stage III or IV were found to predict the death of the child (Paper IV).The findings from this thesis revealed that the need of support for family caregivers during their child’s HIV diagnosis and treatment initiation is part of a continuum of care. It also suggests a context-based guiding procedure and psychosocial support to ease children’s HIV disclosure and minimize the risk of fear of HIV stigma, providing medication reminders, careful selection of ART regimens and improving child–caregiver communication. In addition, there is a need to pay greater attention to younger children as they are at greater risk of death due to lower blood hemoglobin and as they have developed advanced disease at treatment initiation.