About 38,000 people live with chronic Hepatitis C in Scotland and it is estimated a further 18,000 are unaware they have the blood-borne virus, which can infect and seriously damage the liver, according to Health Protection Scotland statistics.
Figures for 2011 show there were 146 liver-related deaths in Scotland among people diagnosed with the virus.
A national campaign titled "Ever injected? Get tested" is being backed by charities and NHS boards to make help people who are unaware they have the illness access treatment.
Those most at risk include people who currently inject or have a history of injecting drugs, steroids, performance- enhancing drugs or tanning products, the campaign said.
Leon Wylie, lead officer of Hepatitis Scotland, said: "World-class care can only be given if people know they have the virus. Current and emerging treatments are a step-change from the original treatments of the 1990s.
"The message is, you need to get a test if you have been at risk - if you have the virus it is highly curable."
The month-long campaign features adverts on public transport and online and takes in World Hepatitis Day on July 28.