Blood pressure information measurement device includes cuff including first and second fluid bag accommodated in first fluid bag, pressure increase/reduction mechanism configured to increase and decrease pressure in first fluid bag internal space and pressure in an internal space of second fluid bag, control unit configured to control operation of pressure increase/reduction mechanism, pressure detection device configured to detect first fluid bag internal pressure, and calculation unit configured to calculate blood pressure information. In calculating blood pressure information, control unit is configured to pressurize second fluid bag internal space with pressurization of internal space of first fluid bag being stopped, and after second fluid bag internal pressure increases until difference in pressure between internal pressure of second fluid bag and internal pressure of first fluid bag reaches predetermined value, pressurize both internal spaces of the first and second fluid bags such that difference in pressure is kept at predetermined value.
