Previous research has shown that childhood body size is associated with blood pressure in adulthood, and that early and rapid growth rates are correlated with adverse cardiovascular outcomes. Our objectives are to estimate associations between childhood body size growth parameters and adult blood pressure, and to examine the effect of early attainment of critical growth milestones on adult blood pressure, relative to normal or late attainment. Lifetime height and body mass index (BMI) measurements in childhood, and systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements in adulthood are taken from participants in the Fels Longitudinal Study. Childhood growth curves are estimated separately for stature and BMI using the Preece-Baines and third-degree polynomial models, respectively. Associations between the resulting parameter estimates and adult blood pressure are then examined using linear mixed models. Our findings show that the ages of achievement of the stature-based growth onset and peak velocity, as well as the age of achievement of the BMI-based adiposity rebound, are negatively associated with adult blood pressure, implying that early height or BMI growth can lead to increased blood pressure in adulthood. There were subtle differences in these relationships based on age and gender, and also between SBP and DBP. These results expand on the existing literature, showing that not only childhood body size, but also the timing of childhood growth can have a deleterious effect on adult cardiovascular health.