Smithfield Foods Inc. honored its long-term relationship with a local doctor on Wednesday by making a donation in his name to the free clinic in Suffolk where he now spends much of his retirement.

The contribution — $50,000 that the Western Tidewater Free Clinic can use without restrictions — turns out to be the largest single donation ever given to the organization by a single company.

“At Smithfield Foods, we strongly believe that it’s our responsibility to give back to the communities where our employees live, work and raise their families,” Smithfield Foods President and CEO C. Larry Pope said in a statement released Wednesday afternoon.

“Dr. Bernard Jamison is a longstanding friend of the company and the local community, and we are pleased to provide support to the Western Tidewater Free Clinic to assist our fellow residents.”

Jamison, who emigrated to the United States from Northern Ireland as a young doctor, started a solo medical practice in Smithfield in 1961. He was joined several years later by Dr. Desmond Longford, and the two grew the practice into what is now known as the Smithfield Medical Center, he said Wednesday.

Early in his service to the town and its residents, Jamison became the Luter family doctor, and he was the packing company’s on-call physician “from Day One,” he said.

Today, he and Dr. Longford serve as the co-medical director at the free clinic, and he’s been part of the team there since the project was conceived.

Having retired in 2005 after 50 years in the practice of medicine, he said, working at the clinic is something he owes to the community that supported him.

“Payback is the way I look at it,” he said. “It’s my way of giving back to the community.”

And even though Wednesday’s donation represented a kind of payback for — or at least recognition of — his service to Smithfield Foods and the Smithfield community for so many years, Jamison was uncomfortable looking at it that way.

“I don’t like to think of it that way,” he said. “I like to think of it as a donation to the clinic and all the people there. I’m very touched, but I’m not the only one working there.”

Doris Salem, the executive director for WTFC, was ecstatic about the donation.

“It’s a tremendous help,” she said. “We graciously accept it and are pleased to have it.”

The clinic, which also serves Franklin, Southampton County and Isle County, began operating out of new, larger quarters in October, thanks in large part to a grant from the Obici Foundation.

Since its 1,400 patients are treated free of charge, the only income for the clinic comes from grants and donations, Jamison pointed out.

“We are very dependent on donations and grants,” he said. “A lot of people have been very generous. If not, (the clinic) wouldn’t be there.”