Poverty, while not a disease process, is well-known to have far-reaching effects on the health of children and adolescents. In developing countries, poverty is associated with inadequate shelter, unsafe water and inadequate nutrition, leading to increased rates of infectious diseases, including malaria and diarreal illnesses, as well as increased rates of infant and maternal mortality. Even in wealthy, industrialised countries, poverty negatively impacts on child health, starting life with increased rates of prematurity, low birth weight and maternal depression, and continuing into childhood with increased rates of asthma, dental caries, inadequate or inappropriate nutrition, as well as increased exposure to trauma and abuse, violence and crime. By the time these children become teen-aged patients in our clinic, they have increased rates of aggression, mental health problems and delinquent behaviours, as well as lower reading and math scores and increased rates of prematurely leaving their education. In this book edited by two leading experts we have asked people from different parts of the world to focus on the comorbidities of poverty.