The World Health Organization estimates that almost half of all premature deaths among 15- to 19-year olds can be attributed to injuries with most (95%) fatal injuries occurring in low- and middle-income countries. Yet the evidence base for adolescent injuries in low-income countries is poor. This article uses a mixed method approach to gain an understanding of patterns, causes and consequences of unintentional injuries among adolescents aged between 14 and 16 years in four low-income country settings. Survey data collected in 2009 in Ethiopia, India (Andhra Pradesh), Peru and Vietnam (from ~900 adolescents in each country) were integrated with qualitative research (conducted between 2007 and 2011) with a nested sample of older cohort children in Ethiopia (n = 25) and India (n = 25) using an iterative process. Logistic regression models were fitted to examine potential risk factors for injuries. Injuries were a concern for adolescents in all countries and occurred during work, recreation and sports or transportation. Being male was associated with an increased risk for all types of injuries, whereas being poor was only significantly associated with work injuries. Area of residence (urban vs rural) made a difference in some countries and for some kinds of injuries as did perceived health status. Qualitative findings highlight the consequences of injuries not only for the adolescents but also for the social and economic status of the entire household. Injury prevention programmes need to be specific to cultural and environmental settings, expectations of adolescent's responsibilities and responsive to the context of poverty.