Osteoporosis is a major public health problem through its association with fragility fracture. Low peak bone mass (PBM) is a major contributor to later osteoporosis risk. Despite this, most studies concentrate on older people when the window of opportunity to impact PBM has passed. This study aimed to understand what adolescents and young adults understand about PBM, the risk of osteoporotic fracture and how lifestyle factors impact PBM. Such information may inform educational interventions to reduce future risk of fracture, and provide important public health benefits. New Zealand university students were approached to participate in this study. Nine focus groups of a total of 44 adolescents and young adults, mean age 22.9 (± 4.02) years of different ethnicities (29 female 15 male), were conducted using a semi-structured approach with open-ended questions and prompts. Transcripts were thematically coded using an inductive content analysis approach. Participants reported poor knowledge of PBM and factors impacting risk of osteoporotic fracture. There was a general awareness of the positive and negative impacts of many lifestyle behaviours such as physical activity, diet, tobacco smoking and alcohol consumption on health in general, but not specifically how these impact PBM and good bone health in later life. We conclude that in a cohort of New Zealand University students, current knowledge of osteoporosis and lifestyle factors that impact PBM is limited. Educational interventions in young adults are now warranted to improve PBM and prevent osteoporosis in late adulthood.