LEXINGTON, Ky. — President Bush’s nominee for surgeon general, Kentucky cardiologist James Holsinger, has come under fire from gay-rights groups for, among other things, voting to expel a lesbian pastor from the United Methodist Church and writing in 1991 that gay sex is unnatural and unhealthy.

Also, Dr. Holsinger helped found a Methodist congregation that, according to gay-rights activists, believes homosexuality is a matter of choice and can be “cured.”

“He has a pretty clear bias against gays and lesbians,” said Christina Gilgor, director of the Kentucky Fairness Alliance, a gay-rights group. “This ideology flies in the face of current scientific medical studies. That makes me uneasy that he rejects science and promotes ideology.”

Dr. Holsinger, 68, served as Kentucky’s health secretary and chancellor of the University of Kentucky’s medical center. He taught at several medical schools and spent more than three decades in the Army Reserve, retiring in 1993 as a major general.

His supporters, including fellow doctors, faculty members, and state officials, said he would never let his theological views affect his medical ones. “Jim is able, as most of us are in medicine, to separate feelings that we have from our responsibility in taking care of patients,” said Douglas Scutchfield, a professor of public health at the University of Kentucky.

In announcing Dr. Holsinger as his choice for America’s top doctor May 24, Mr. Bush said the physician will focus on educating the public about childhood obesity. The previous surgeon general was Richard Carmona, whose term was allowed to expire last summer. Dr. Carmona issued an unprecedented report condemning second-hand smoke.

Dr. Holsinger received his bachelor’s degree from the University of Kentucky, master’s degrees from the University of South Carolina and Asbury Theological Seminary, and a doctorate and medical degree from Duke University.

Mr. Scutchfield said Dr. Holsinger has advocated expanded stem-cell research, in opposition to many conservatives, and also has shown political courage in this tobacco-producing state by supporting higher cigarette taxes to curb teen smoking.

Governor Fletcher commended Dr. Holsinger for working to fight obesity and other health problems in this Appalachian state, which ranks near the bottom in many categories. “He helped get the ball rolling and focusing on healthy lifestyles,” Mr. Fletcher said.

As president of the Methodist Church’s national Judicial Council, Dr. Holsinger voted last year to support a pastor who blocked a gay man from joining a congregation. In 2004, he voted to expel a lesbian from the clergy. The majority of the panel voted to keep the lesbian associate pastor in place, citing questions about whether she had openly declared her homosexuality, but Dr. Holsinger dissented.

Sixteen years ago, he wrote a paper for the church in which he likened the reproductive organs to male and female “pipe fittings” and argued that homosexuality is therefore biologically unnatural.

“When the complementarity of the sexes is breached, injuries and diseases may occur,” Dr. Holsinger wrote, citing studies showing higher rates of sexually transmitted diseases among gay men and the risk of injury from anal sex.

Dr. Holsinger wrote the paper at a time when the church was one of numerous denominations considering a more open stance on allowing practicing homosexuals to join. It took that step in 1992, saying gays are of “sacred worth” and should be welcomed. Practicing homosexuals are still prohibited from serving in the clergy.

As for the congregation Dr. Holsinger helped establish, Hope Springs Community Church, the Reverend David Calhoun told the Lexington Herald-Leader last week that the Lexington church helps some gay members to “walk out of that lifestyle.”

The National Gay and Lesbian Task Force, which is opposing the nomination along with the Human Rights Campaign and other local and national groups, calls such a practice “nothing short of torture” for gays.

Phyllis Nash, who worked under Dr. Holsinger for nine years as vice chancellor at the medical center, said the views he took in church appear at odds with his professional actions.

She recalled a women’s health conference that Dr. Holsinger helped organize in 2002 that included a session on lesbian health. Despite complaints from some lawmakers, Dr. Holsinger insisted the session go forward, she said.