This study's objective was assessment of cardiovascular disease (CVD) risk factor knowledge in young adults, its association with 10-year changes in risk factor levels, and variables related to risk factor knowledge. A total of 4,193 healthy persons (55% female, 48% Black; mean age = 30 years) from four urban US communities were queried about risk factor knowledge in 1990-1991 and were reexamined in 2000-2001. Of six risk factors considered (hypertension, hyperlipidemia, smoking, overweight, sedentary lifestyle, and unhealthy diet), participants mentioned a mean of two; more than 65% were not aware of any risk factors, and less than 35% recognized being overweight as a risk factor. After adjustment, variables associated with mentioning more than two CVD risk factors versus one or fewer were Black race (OR = 0.52, 95% confidence interval (CI): 0.44, 0.61), having a high school education or less (OR = 0.88, 95% CI: 0.80, 0.95), having one or two (vs. zero) risk factors (OR = 1.27, 95% CI: 1.05, 1.53), and having three or more (vs. zero) risk factors (OR = 1.79, 95% CI: 1.35, 2.38). More knowledge was marginally associated with less increase in body mass index 10 years later (p = 0.06) but was unrelated to other risk factor changes. Knowledge of CVD risk factors was very low in these young adults but increased with the presence of risk factors. Knowledge alone did not predict 10-year changes in risk factors.