The effect of time elapsed after standing on the orthostatic change in blood pressure was investigated. The study subjects were recruited from 237 community-dwelling elderly residents free from any history of cardiovascular disease and not on medication. Basal blood pressure was determined by averaging two determinations of supine blood pressure measured with an automatic oscillometric blood pressure recorder after resting for more than 10 minutes. Orthostatic change in systolic blood pressure (SBP) was determined as more than a 10% increase or decrease in SBP after standing. In the total population, maximum change in SBP was observed at 1 minute after standing-up. However, 8.4% and 7.2% of subjects showed abnormal increase or decrease in SBP only after 3 minutes. These results suggests that orthostatic dysregulation of blood pressure could be evaluated by measuring at 1 minute after standing up. However, if abnormal variation of blood pressure was not observed at 1 minute after standing up, repeated measurement at 3 minutes would be necessary.