The one-hour faceoff, hosted by Skidmore College, at times focused more on state issues than federal, but served to draw distinctions in a race that has flown under the media radar.
Gillibrand is running for her first full, six-year term after being appointed to replace Hillary Rodham Clinton as New York's junior senator in 2008 and then winning a special election in 2010 to complete Clinton's term.
Long, trailing badly in the polls, came out firing. She said the Democrat "hasn't done anything" to cut federal spending and create jobs in New York. She accused Gillibrand of a "180-degree" flip on gun control and of "completely misleading the people" on the likelihood of abortion being overturned either by the courts or Congress.
"My initial question to you is, what have you done to bring back jobs back to New York State -- and the answer really is nothing," Long told Gillibrand.
Gillibrand played up bipartisanship, mentioning her work with Rep. Peter King (R-Seaford) on security issues and touting agreements to increase health benefits for 9/11 first responders.
But the incumbent also tried to brand Long as an extreme conservative with a "slash-only approach" to federal spending who was also "out of touch" on women's issues.
The abortion issue triggered some of the most pointed exchanges in this, the first U.S. Senate contest in New York to feature two women as the major-party candidates.
Long called Roe v. Wade a "bad constitutional decision" and if it were overturned it would appropriately, in her opinion, make abortion a state-driven question.
"New York wouldn't have the same [abortion] policy as Iowa," Long said. "Each state could have the policy it wants."
The GOP-led House, Gillibrand countered, made a priority of trying to eliminate funding for Planned Parenthood and allow employers to dictate what type of contraceptive health care insurance their employees could receive.
Long said Gillibrand had switched from a gun-rights supporter when she was an upstate congresswoman to a gun-control advocate as a senator -- noting that the National Rifle Association graded Gillibrand an "A" then and an "F" now. It was a charge Gillibrand did not dispute.
"My values have never changed," she said. "What is different is that we have gun-violence issues in New York State that weren't as prevalent in my old district." The two also differed when asked what U.S. Supreme Court justice they most admired. Gillibrand picked the liberal Sonia Sotomayor. Long, who once clerked for Clarence Thomas, didn't name one but rattled off three conservatives: Thomas, Sam Alito and Chief Justice John Roberts.
They also disagreed on the pace of natural gas exploration with Gillibrand wanting to wait for more studies and Long saying New York is moving too slowly. And Long said President Barack Obama hasn't been a strong enough supporter of Israel; Gillibrand vociferously disagreed.
Asked to name one issue on which she could agree with President Barack Obama, Long first said the president wasn't sufficiently bipartisan, and then concluded: "If he's interested in reducing the debt, in reducing our budget deficit, I'd be willing to with him on that."
Gillibrand seemed to strive for more middle ground when asked the same about Republican presidential candidate Mitt Romney.
"I suspect we could agree on some national security issues," she said. "National security issues tend be less partisan."