Euan and Arran Macleod were both diagnosed with a rare and "life-limiting" genetic condition that means they cannot fight infections.
But parents Janet, 43, and Calum, 45, were delighted to learn that donors have been found for both Euan, six, and Arran, four.
The stem cell transplant operations are due to take place in August or September.
"Bone marrow donors have been found for both the boys and are excellent matches, which is wonderful news," said Janet, from Upper Dounreay, Caithness.
Six-year-old Euan and Arran, who is four, have chronic granulomatous disorder (CGD), which weakens the immune system. Although it is genetic there is no history of the condition on either side of the family. It is extremely rare, affecting only between 250 and 280 people in the UK.
Doctors have told the boys' parents that without the operation Euan's life expectancy would be mid-teens, and Arran's mid-30s. They would also have to avoid animals, crowds of people, vegetation and many other infection risks.
In June last year, Euan became seriously unwell and was airlifted to Yorkhill hospital in Glasgow in a coma, where he was diagnosed with an abscess on his brain. After successful emergency treatment, doctors discovered that he had CGD.
Following the devastating news, Janet and Calum launched an appeal on behalf of their sons to raise awareness of the bone marrow register and encourage people to sign up. They also started raising money for the Anthony Nolan Trust.