Background One previous large cross-sectional study across four countries suggests that riboflavin intake may be inversely associated with blood pressure. Objective The aim of this analysis was to investigate a possible association between riboflavin intake and change in blood pressure over 5 years. Methods The study population comprised Chinese men and women who participated in the Jiangsu Nutrition Study. Quantitative data relating to riboflavin intake at baseline in 2002 and measurements of blood pressure at baseline and follow-up in 2007 were available for 1,227 individuals. Results Overall, 97.2% of the participants had inadequate riboflavin intake (below the Estimated Average Requirement). In multivariable analysis adjusted for sociodemographic and lifestyle factors and dietary patterns, a higher riboflavin intake was inversely associated with change in systolic blood pressure ( p = .036). In participants taking antihypertensive medication at baseline, the relationship between riboflavin intake and systolic blood pressure persisted; whereas, in those not taking antihypertensive medication, the diastolic blood pressure was less likely to increase with the increasing intake of riboflavin ( p = .031). There was a three-way interaction between antihypertensive medications, body mass index, and riboflavin intake. Among those who were obese and taking antihypertensive medication, a higher riboflavin intake was associated with a smaller increment in systolic blood pressure and pulse pressure. Conclusions There are complex interactions between riboflavin intake and blood pressure change that depend on prior antihypertensive use and the presence or absence of obesity.