Blood stock levels around the country have fallen due to increased cancellations due to illness and the annual dip over the summer months when people go abroad.
Donors with O positive are particularly needed but donors of all blood types are welcome.
The sessions are as follows:
The John Pounds Centre on Queen Street in Portsmouth, on Tuesday, July 5, which is only 78% full.
Waypoint Church on Hunts Pond Road in Fareham, on Wednesday, July 6, which is only 70% full.
Thorngate Hall on Bury Road in Gosport on Thursday, July 7, which is only 66% full.
You can make the appointment at www.blood.co.uk, by calling 0300 123 23 23 or downloading the NHS Give Blood app.