OBJECTIVE: Previous longitudinal studies suggest that depression and anxiety are associated with risk for cardiovascular disease. The aim of the present study was to test whether an association between depression and anxiety symptoms and retinal vessel caliber, an indicator of subclinical cardiovascular risk, is apparent as early as adolescence and young adulthood. METHODS: Participants were 865 adolescents and young adults who participated in the Brisbane Longitudinal Twin Study and the Twin Eye Study in Tasmania. Participants completed an assessment of depression/anxiety symptoms (the Somatic and Psychological Health Report) when they were 16.5 years old (mean age), and they underwent retinal imaging, on average, 2.5 years later (range, 2 years before to 7 years after the depression/anxiety assessment). Retinal vessel caliber was assessed using computer software. RESULTS: Depression and anxiety symptoms were associated with wider retinal arteriolar caliber in this sample of adolescents and young adults (β = 0.09, p = .016), even after adjusting for other cardiovascular risk factors (β = 0.08, p = .025). Multiple regression analyses revealed that affective symptoms of depression/anxiety were associated with retinal vessel caliber independently of somatic symptoms. CONCLUSIONS: Depression and anxiety symptoms are associated with measurable signs in the retinal microvasculature in early life, suggesting that pathological microvascular mechanisms linking depression/anxiety and cardiovascular disease may be operative from a young age.