Central artery stiffening increases the haemodynamic pulsations transmitted downstream towards target organs, including the brain. While recent evidence suggests that long duration spaceflight is associated with reduced common carotid artery (CCA) distensibility, cerebrovascular pulsatility has not been extensively characterized in astronauts. This study investigated changes in pulsatility from pre-flight to after 6 months in space, using a secondary analysis of data from four separate experiments. Middle cerebral artery blood velocity (MCAv) was measured during supine rest in 27 astronauts (20 men, 7 women). In subsets of this cohort, we measured CCA distensibility and β stiffness (n = 20), and CCA wave intensity (n = 12). The overall increase in MCAv pulsatility index (PI