The veteran news presenter, 66, was diagnosed with stage 4 bowel cancer in 2014.
Now he was pleased to reveal he had reunited with his BBC colleagues after several months of cancer treatment.
Taking to social media, Alagiah explained it felt good to be back with his News at Six colleagues and in the BBC studios.
“I’ll be back in the @BBCNews studio today after months of treatment,” Alagiah told his social media followers. “Pure coincidence - it’s 8 years to the day since I was told I had stage 4 #bowelcancer. So good to be with the News at Six team again.”