PurposeThis study aims to describe the prevalence of self-reported chronic health conditions among high school students in New Zealand, the extent to which the condition impacts on their activities and socialization, and to explore the association between the level of impact of the illness or disability and the emotional well-being of students with chronic health conditions. MethodsA two-stage cluster sample of 9,107 students (Years 9–13) from 96 New Zealand high schools participated in a 2007 health survey using internet tablets. Students were asked about any chronic illness or disabilities lasting more than 6 months, the impact of the illness or disabilities on their daily activities and socialization, and their depressive symptoms (RADS-SF) and emotional well-being (WHO-5). ResultsAlmost one in five students (18%) reported a chronic health condition. Among them, 28% reported an impact of their illness or disability on their activities, and 8% reported an impact on their ability to socialize. High levels of depressive symptoms were found among students with chronic health conditions reporting that their illness or disability impacts their activities (18%) or their ability to socialize (40%), and this was significantly higher than among students without chronic health conditions (10%). ConclusionsOur findings suggest that there is a large group of adolescents with chronic health conditions for whom their illness or disability has an impact on their daily activities and ability to socialize with their peers. These students are more likely to experience emotional distress and require support and opportunities for healthy youth development.