This book provides the details of research conducted to address a critical issue of public health relevance, namely paediatric HIV treatment with antiretrovirals (ARVs). It focusses on the investigatation of the key issue of adherence:how to measure it,frequency and its determinants. Paediatric adherence is a true challenge for parents and health workers faced with proposing life-long treatment with incompletely adapted drug regimens to children sometimes as young as neonates. The research focussed on a study population with a mean age of 27.08mths in South Africa. The necessity for high levels of adherence to the exacting regimens of ARV treatment is now an accepted fact and much research has focussed on the measurement, predictors and interventions of adherence in adults.However, there is a paucity of data on assessing these same factors in the context of paediatric adherence. The work included in this research is unique, relevant and a contribution to new knowledge in the field especially its focus on the paediatric population younger than 7 years of age. The findings and recommendations have particular relevance for resource-poor settings.