Like a proud father, Barry Rabner beamed and shook a lot of hands Tuesday morning. The CEO of the University Medical Center at Princeton had barely slept the night before, as final preparations were made to move the hospital’s staff and patients from the old building on Witherspoon Street to its gleaming new home in Plainsboro, three miles away.

But Mr. Rabner showed no signs of fatigue as he welcomed patients to the $522.7 million medical complex that took four years to build. Transported by ambulance, the patients on stretchers began arriving about 7:30 a.m. Some smiled and took in their new surroundings. Others, in more serious condition and accompanied by their doctors, appeared to sleep through the momentous occasion.

Some 110 patients were being transferred from the old hospital in Princeton Borough to the new one across Route 1. The process, mapped and choreographed to the minute, was projected to take about six hours. A sign outside the entrance to the emergency room of the old hospital was in place by early morning, directing people to the new building and instructing them to call 911 if they needed emergency transportation.

“How cool is this?” said Mr. Rabner, who strolled up and down the light-filled lobby hallway of the new building, surveying the action. “What’s really great is seeing all the nurses with their noses pressed against the windows. Everyone is talking about it С and not just about the place itself. They are so excited, because they want to change the way care is delivered. It’s all been about taking care of the patients in a new way.”

The 636,000-square-foot hospital is the centerpiece of a 171-acre site that, when completed, will include a nursing home, age-restricted housing, a research building, a day care center, a park, and additional facilities. Merwick Rehabilitation Center is already located on the property. The hospital was designed to take advantage of green technology and sited to maximize natural light. All of the 231 single-patient rooms have large windows and expansive views.

Dr. Daniel Farber, an emergency room physician at the hospital, paused in the hallway to shake Mr. Rabner’s hand. “It’s a wonderful thing,” he said. Numerous people have been offering their congratulations, Mr. Rabner said, from the doctors to the housekeeping staff. “Even the volunteers, and we have over a thousand of them, are just as jazzed up as the people who are paid to be here,” he said.

Smita Shah, a hospice volunteer, was among those on hand to help new patients and their families on opening day. Ms. Shah, who lives in East Windsor, has been a hospital volunteer for years. “How could I miss out on this unique event?” she said. “I think this is an excellent facility and it will be a great service to so many people.”

Up on the maternity floor, Nicole Williams was bonding with baby Atticus, born Monday at the old hospital and the first baby to be transported to the new building the following day. Settled into her room, Ms. Williams marveled at the color-coordinated sheets and the view from her picture window. “It’s really open. You can see a lot more, and I think that makes you feel better,” she said.

Nurse and lactation consultant Dee Vandegrift, proud to be the first in the hospital to handle a baby, described the opening day as “an overwhelming feeling of excitement.” Ms. Vandergrift worked in the old building for 15 years. “The techniques we use will be so much more advanced here,” she said. “Medicine is changing, and this hospital will allow for that change.”

The hospital has been a fixture in Princeton Borough for the past 93 years. Leaving the Witherspoon Street location was emotional for some. A few weeks ago, a farewell ceremony was held in front of the building. On Tuesday at 5:15 a.m., staff members involved in the move gathered in the old hospital for the last time.

“It was very sad,” said Mr. Rabner. “The hallways are empty. All the pictures are taken down. There are people who have worked in that building for decades, like Hettie Dean — she’s been there for 56 years. One family has 26 members working there. It’s a huge tradition for them.”