Sanders gained 44 percent of voter support against Clinton’s 37 percent, the poll revealed.
US Vice President Joe Biden, who has still not decided whether to join the race, gained 9 percent of the votes.
New Hampshire is the first state to hold primary elections for Republican and Democrat presidential candidates. Its outcome plays a major role in determining the selection of the presidential candidates from the two major political parties.
About 50 percent of likely primary voters said they could support Clinton’s presidential bid, but underscored lack of enthusiasm about it, according to the poll.
In the national polls, Hillary Clinton is still the Democratic Party frontrunner, leading Sanders by more than 35 points, according to the latest report by Public Policy Polling.