The trial over allegations of campaign finance violations was scheduled to begin on Jan. 30.
The former political star, known for his trademark smile and never shying away from a camera, went out of his way not to be photographed on Friday, sneaking through a back door. Reporters inside the courtroom said he looked pale and gaunt.
His lawyers provided the judge two letters from his cardiologist saying he has a "real and serious" heart condition requiring immediate attention. Lawyers argued that Edwards' condition would make it difficult to attend the trial if it began as scheduled and requested a delay of at least two months.
It was revealed during the hearing that Edwards had three "episodes" and needed surgery in February.
The judge granted the request, delaying the trial to March 26. But it may be delayed again if more medical procedures are necessary.
What a fall it has been for the 2004 Democratic vice presidential nominee. Just four years ago, he was a leading Democratic contender for president. At the time, his wife Elizabeth campaigned with him despite her breast cancer diagnosis.
But it turned out, Edwards was cheating on his wife at the time with Rielle Hunter. He fathered a child with her, but for years denied it.
Since Elizabeth Edwards lost her battle with cancer, John Edwards has been raising their two young children as a single parent.
Edwards faces six felony and misdemeanor counts related to nearly $1 million from wealthy donors used to help hide the Hunter story during his 2008 While House run - charges Edwards denies.
The Associated Press contributed to this report