Unison members will begin two days of campaigning for a "significant pay rise" of at least £2,000.
The workers - including nurses, midwives, paramedics, cleaners, domestics and porters - will be taking to social media as well as holding a virtual pay rally on Tuesday to call for a "fair" pay rise.
Christina McAnea, Unison's general secretary said: "Since the start of this pandemic, our NHS workers have shown immense dedication, commitment and compassion and it's time they're fairly rewarded.
"That's why Unison is fighting for all health workers to get a £2,000 pay rise.
"The Scottish Government is paying staff a £500 'bonus' in February.
"That's a welcome acknowledgment that staff have gone above the call of duty in the past year but it isn't the full pay rise they deserve - that's why our campaign is continuing.
"Investing in the NHS and its incredible staff is a must for the government. It would help the health service tackle the mounting staff shortages that were already causing huge problems even before the virus hit.
"An early pay rise would also be the country's best way of saying a heartfelt thank you to every single member of the NHS team."
Tom Waterson, chair of Unison Scotland's health committee, said: "Our dedicated NHS staff have suffered real-term pay cuts over the past decade with significant extra costs over these last few months.
"A £2,000 pay rise for everyone is fair, reasonable, simple and could be implemented quickly."