Almost two-thirds of Finnish military officers believe their country should join NATO and even more think the Russian military threat has grown in the wake of the Ukraine crisis.
The crisis has brought relations between Russia and the West to their lowest ebb since the Cold War.
A poll showed on Saturday that 66 percent favoured NATO entry, 10 percent preferred a defence alliance with Sweden and a quarter thought it would be best to remain outside any alliance.
About three quarters of respondents said the Ukraine crisis had made them view NATO membership more positively, and slightly more said the Russian military threat against Finland had increased.
Some 2000 of the 6000 members of the Officers' Union were part of the survey, which was conducted by the Helsingin Sanomat newspaper last week.
However, support for NATO membership remains low among the general population, with recent polls showing only about one in five favouring entry.