Dozens of Iranian immigrants gathered on a recent night in Dupont Circle for a get-out-the-vote event, pondering the choice facing them.

Apple martinis or cosmopolitans?

"Look at us. We're in a bar. We're Iranians. None of us has trouble with a cocktail or two," said Daniel Rostrup, 23, of Columbia Heights, lifting his cosmopolitan to indicate the crowd of professionals in slinky sweaters and fashionable heels.

Iranians represent the largest Middle Eastern immigrant group in the Washington area but one of the least visible. Many are highly educated professionals who are secular. Think Chanel, not chador.

Settled in such suburbs as Potomac and Tysons Corner, they are a world away from the fundamentalist Islamic government in their homeland.

Or so they thought.

But since the Sept. 11, 2001, terrorist attacks, the community has been startled by a crackdown on Middle Eastern visitors and a flurry of job-discrimination cases involving Iranian Americans. In response, the immigrants are venturing into the one area of American life that had remained out of their realm: politics.

"There came a realization that without actively engaging in the American civic and electoral process, our voices were not going to be heard," said Morad Ghorban, political director of the new Iranian American Political Action Committee.

While they are a relatively small group -- estimates of the nationwide population range from 340,000 to a half-million or more -- Iranian Americans are working the system to maximize their influence. Activists have registered hundreds to vote. The Iranian American PAC has distributed about $30,000 to congressional and local candidates on Tuesday's ballot. And the Iranian American Bar Association has taken the community's civil-liberties complaints to dozens of congressional staffers.

"Iranian Americans realize that, 'Okay, I may be CEO of my own company, but I still can't bring my grandmother here without her being humiliated in the airport,' " said Dokhi Fassihian, executive director of the National Iranian American Council, a two-year-old organization based in Adams Morgan that organized the voter registration drive.

Most Iranians who have settled in this country did so about 1979, when the Islamic revolution toppled the U.S.-backed shah. Although the biggest share headed for Southern California, thousands came to Washington, which had a sizable Iranian student population. The 2000 Census counted 17,390 Iranian-born residents in this area, but activists think there are more.

With their roots in Iran's elite, the immigrants are generally highly educated, with a median family income 20 percent higher than the U.S. average, according to the Iranian Studies Group at the Massachusetts Institute of Technology. That prosperity is obvious in the Washington area.

There are associations of dentists, lawyers, professors and high-tech executives. When the Iranian American Technology Council threw a benefit last year, it was a black-tie, $175-a-ticket dinner at the Four Seasons.

But in this city of politics, Iranian Americans were invisible. They were too busy working. And they rarely formed alliances with established groups from the Middle East. Iranians are ethnic Persians, not Arabs; and many are secular Muslims or not Muslim at all.

"They just wanted to lay low, make money, get over the trauma they experienced in their own country before coming here, do well for themselves and their kids," Fassihian said. "And then they realized this isn't going to happen . . . unless we became active as citizens in this country."

The political awakening was driven by new security measures after the Sept. 11, 2001, attacks. Among other steps, Congress considered sharply limiting visas for citizens of nations designated as sponsors of terrorism, including Iran. In the end, the State Department simply required more security checks.

But the focus on Iran stunned the immigrants, who realized they were not so far removed from the mullahs in Tehran -- at least in the minds of many Americans.

"The image of an Iranian is someone with a beard, a fanatic in the street yelling anti-American slogans," Babak Hoghooghi said.

Hoghooghi has no beard. He wears a yellow French silk tie and a well-cut suit from Bloomingdale's. He sits in an elegant conference room at Skadden, Arps, Slate, Meagher & Flom, the high-powered Washington firm where he is a lawyer.

"One of our goals is to rebuild the image, so it is a reflection of the reality of who we are," said the 40-year-old Potomac resident, a founder of the Iranian American Bar Association.

Hoghooghi said he isn't opposed to more scrutiny in the visa process to better protect the United States. "We live here too," he said.

But his group has said that authorities should focus less on the nationality of immigrants than on behavioral or background information that raises questions.

The visa measure wasn't the only concern among Iranian Americans. Several have reported cases of job discrimination. Others, like Fassihian, said they have been denied security clearances because of their travel or personal ties to Iran.

Perhaps the biggest outcry came when the government launched a program in 2002 to register male visitors from two dozen predominantly Muslim countries. Iranians were among the first called to register; hundreds were charged with visa violations and placed in deportation proceedings. Many had relatives here.

U.S. Justice Department officials said the program was necessary to identify visitors from countries where Islamic terrorists had been active.

The Iranian American Bar Association produced a report charging that many detention decisions were made arbitrarily and that immigrants were treated in a humiliating manner.

The lawyers have presented their investigation to dozens of House and Senate staffers and are pressing to get more details about the program, which ended last year.

Some Iranian Americans said they are planning to vote for the Democratic nominee, Sen. John F. Kerry (Mass.), because of concern about civil liberties. But the community is by no means aligned with one political party. Many say they prefer President Bush because of his firm stand toward the Iranian government. The Iranian American PAC, which focuses on domestic issues, has given funds to Democrats and Republicans.

Mehdi Bozorgmehr, a professor at the City University of New York who has studied Iranian Americans, said little information is available on their voting patterns.

"What is important is for the first time, you really are seeing a movement in the community to get the vote out," he said.

Mixers are among the ways the District-based National Iranian American Council reaches out to the community. Iranian American groups have encouraged civic presence since the 2001 terrorist attacks.