The Cardiovascular Risk in Young Finns Study (YFS) is a long-standing cohort study that is following a sample of Finnish individuals from childhood into old age. YFS is a national multi-center study that was originally designed to provide information on the levels of cardiovascular risk factors and their determinants in children and adolescents of various ages in different parts of Finland. The first examination in 1980 recruited 3596 participants aged 3–18 years from five cities and their surrounding rural communities. The cohort has been followed up with large-scale field studies in 1983, 1986, 1989, 1992, 2001, 2007, 2011, and 2018–2020. The participation rates have varied between 61% and 85%. The latest follow-up study was conducted in 2018–2020, and it was extended to cover the original participants and their parents and offspring. At present, the YFS is the largest study in Europe with a follow-up of cardiometabolic and other health-related phenotypes from childhood to adulthood. With over 1300 publications, the study has contributed to the understanding of the development of cardiometabolic risk, including the effects of diet, lifestyle, metabolic risk factors, psychological traits and psychosocial factors, inflammation, hormones, and genetic markers. The focus has primarily been on the research into cardiometabolic health, but the data are increasingly being used to examine many other aspects of human health and well-being.