Another 1000 Australians are being asked to roll up a sleeve and give blood to help save lives this Easter.

Blood wanted.

That's the desperate cry from the Australian Red Cross this Easter long-weekend, when at least 1000 donations are needed to prevent a nationwide shortage.

Some 600 donors are needed on Easter Monday alone.

There is no better way to shake Mondayitis than start the week knowing you've saved three lives per donation, with platelets in high demand, Blood Service spokeswoman Erin Lagoudakis said.

"Platelets are the clotting agent of blood - vital in the treatment of many cancers and to combat life-threatening bleeding from road trauma and in other emergency situations," she said.

"Unfortunately platelets have a shelf-life of just five days which means we can't stockpile them ahead of a long weekend and need continuous donations during this time to meet demand."

She urged people across Australia to give up an hour to donate blood.