Mr Dalby, 68, yesterday made his 115th blood donation through the Australian Red Cross Blood Service, something he's been doing ever since a friend suggested it all those years ago.

"Someone said to me, 'I'm going up to give blood' and explained how it helps people," Mr Dalby said. "I though it sounded like a worthwhile thing so I went along as well.

"It really is a good thing, it helps people no matter who they are and it's just nice to think you've helped somebody who really needs help, and it doesn't matter that you never know who it was."

Each blood donation can help up to three patients in need of a transfusion.

Mr Dalby tries to take an hour every three months to donate blood and he would like to see more people follow his lead.

"I always try to get there every three months.

"There's been some times I haven't been able to because of different circumstances here and there, but I haven't missed too many.

"It's only an hour and it's just a needle in the arm, it's not some big painful procedure and if you're of good health it's something you should consider.

"They check your blood pressure and things like that when you're there so for me I get a free medical every three months as well."

Mr Dalby's blood type is O-negative, the universal blood type that can be used in emergencies when a patient's blood type is unknown, which makes his contribution even more important.

The Red Cross currently has only two days' worth of O-negative blood and needs to boost stocks before winter, when many people can't donate due to illness.

Saturday is World Blood Donor Day and the Red Cross is calling on people to roll up their sleeves.

"World Blood Donor Day is a time to recognise the heroic efforts of [donors], whose every donation helps save three lives," Blood Service spokeswoman Jenna Falkenmire said.

The Mobile Donor Centre will be at Stockland Shellharbour from Wednesday to Friday, June 11-13.

To book a time to donate blood, see the website donateblood.com.au.