Hadamard-encoded ASL (H-ASL) is a time-efficient method for measuring arterial transit time (ATT). The larger encoding matrix extends the scan time, but the accuracy of the ATT with a different encoding matrix was not clarified. This study aimed to propose a practical parameter selection in H-ASL for clinical use. The ATT was not significantly different between 3 and 7 delay encodings. Cerebral blood flow (CBF) obtained with 3 delay encodings with a linear division block design was equivalent to that obtained without encoding. Three delay encodings with a linear division block design provides accurate ATT and CBF within 4 minutes.