"If I continue to work, I would put my retirement at risk, I would put my family at risk," said Su, 65.
His departure leaves the Tri-State area - Washington County, the Eastern Panhandle of West Virginia and south central Pennsylvania - without a board-certified thoracic surgeon, according to Su and Washington County Hospital's public relations department.
Su said his son, William, a vascular surgeon, will continue at the practice they've shared.
Chia-Chuen Su said he performed his last thoracic surgery about six weeks ago, then started directing new patients to surgeons in Baltimore and Washington, D.C.
He's easing into a new life.
Today, he plans to watch himself on CNN, which interviewed him for a piece on medical malpractice. He said the segment is supposed to run sometime after 5 p.m.
He soon will start his new hobby, photography. He already has the instrument he'll need, a digital camera.
Su said he's moving from Hagerstown to a southern state to escape the cold winters that he's never learned to like. He figures that will happen by Christmas.
He doesn't want to leave for at least a few weeks; his first granddaughter is scheduled to be born this month.
Su said he opened his practice in Hagerstown 29 years ago because the area only had one thoracic surgeon. Then, that surgeon died within a year or two, he said, leaving him as the only one.
Su said he has worked, on average, 95 hours a week, seven days a week, with only about five breaks over the years. If he's home by 8 p.m., his wife asks why his day was so short, he joked.
He said he's performed about 1,000 operations a year, which he called a "very high" load.
The gratification of helping a critical patient and the desire to do well have kept him going, he said.
Growing up in Taiwan, Su studied mechanical engineering and thought that would be his career.
He said he switched gears when he saw the pain his father endured from a herniated disc.
Su was accepted to the National Taiwan University School of Medicine in Taipei.
Afterward, he spent a year serving mandatory military service, then came to Durham, N.C., to join his wife, Ching-Hsiang Su, who was working on her doctorate degree in biochemistry at Duke University.
Chia-Chuen Su said he spent one year in an internship at a hospital there, then went to the University of Pennsylvania for a seven-year surgery program.
He came to Hagerstown in 1975, after he completed the program.
Su said he has been sued a few times and lost just once.
Washington County Circuit Court records list only one suit against him. In 1997, a jury found him negligent in the care of a man who died and awarded the man's estate $315,000 and the man's widow $300,000. A portion of the award was lowered two years later, records indicate.
Su said a claim against him that resulted in a 1986 trial damaged his reputation for years.
Su removed a portion of a man's lung because it was thought to be cancerous, according to a news account at the time. The cancer diagnosis, first made before the case was referred to Su, turned out to be false, a news story said.
A jury awarded the man $115,000, but the Maryland Court of Appeals overturned the decision.