A total of 43 percent of voters said health care was "very important" in their decision about who to cast their ballot for as governor, according to the Public Policy Polling survey. Another 24 percent said it was the "most important" issue.
And 24 percent said it was "somewhat important," according to the poll, which was paid for by Save My Care, an Obamacare-defense group.
The poll's findings jibe with other exit polls that showed health care played a key roll in the election of Northam over Republican nominee Ed Gillespie, by a margin of 54 percent to 45 percent.
An NBC News exit poll conducted Tuesday found that health care was the most important issue for voters, with 37 percent of them saying it was their top concern.
Gun policy was a distant second place, with 17 percent, followed by immigration and taxes, which were each named by 14 percent of voters as their most important issue, according to NBC News' poll.
Fifty-three percent of voters polled by PPP said Northam was more in step with their views on the issue of health care, compared with just 39 percent for Gillespie.
Exactly 50 percent of the voters polled said they support the Affordable Care Act, as Obamacare is formally known. A total of 39 percent of voters opposed the law.
Just 20 percent of voters said that Gillespie's support of a Republican effort in Congress to repeal Obamacare made it more likely that they would vote for him, according to the survey. Another 44 percent said it would make them less likely to vote for Gillespie.
In contrast, 47 percent of voters said Northam's opposition to the repeal effort made it more likely that they would support him, compared with 30 percent who said it would make it less likely they would vote for him.
The poll questioned 591 voters and had a margin of error of 4 percent.