Home blood pressure (HBP) measurements are known to be lower than conventional office blood pressure (OBP) measurements. However, this difference might not be consistent across the entire age range and has not been adequately investigated. We assessed the relationship between OBP and HBP with increasing age using the International Database of HOme blood pressure in relation to Cardiovascular Outcome (IDHOCO). OBP, HBP and their difference were assessed across different decades of age. A total of 5689 untreated subjects aged 18-97 years, who had at least two OBP and HBP measurements, were included. Systolic OBP and HBP increased across older age categories (from 112 to 142 mm Hg and from 109 to 136 mm Hg, respectively), with OBP being higher than HBP by ∼7 mm Hg in subjects aged >30 years and lesser in younger subjects (P=0.001). Both diastolic OBP and HBP increased until the age of ∼50 years (from 71 to 79 mm Hg and from 66 to 76 mm Hg, respectively), with OBP being consistently higher than HBP and a trend toward a decreased OBP-HBP difference with aging (P<0.001). Determinants of a larger OBP-HBP difference were younger age, sustained hypertension, nonsmoking and negative cardiovascular disease history. These data suggest that in the general adult population, HBP is consistently lower than OBP across all the decades, but their difference might vary between age groups. Further research is needed to confirm these findings in younger and older subjects and in hypertensive individuals.