While the 'Culture Health Check' report found that more than 90 percent of athletes and staff felt proud to be part of their programme, it also identified a number of key areas where improvement was needed.
Some 31 percent of athletes 'disagreed or strongly disagreed' when asked whether they had opportunities to give feedback without fear of negative consequences.
"That is a concern," UK Sport chief executive Liz Nicholl told reporters.
"It is a significant number fearing the consequences. That’s something we’ll follow up with the sports. It’s about having an open relationship based on mutual respect."
Among the 682 elite athletes from summer sports who completed the survey, 30 percent replied yes when asked whether they had ever witnessed or experienced unacceptable behaviour in their programme.
However, only 24 percent of that number formally reported it to their national governing body and none of the cases resulted in disciplinary measures.
UK Sport's head of culture James Bell said the question had not been time limited.
"We had some examples of people who had ticked that box but they are talking about historical events that happened," he said. "In one case in the (2000) Sydney Olympic cycle."
Thirteen percent said they had witnessed unacceptable behaviour and 17 percent experienced it.
The report, reflecting the anonymous feedback of elite athletes, staff and stakeholders, comes after allegations of sexism and bullying in some of Britain's leading Olympic and Paralympic sports.
An independent review into British Cycling, one of the country's best-funded and most medalled sports, in June last year spoke of a "culture of fear" within the organisation.
Gymnastics, swimming, canoeing and bobsleigh have also suffered allegations of inappropriate behaviour amid criticism of what some see as a "win-at-all-cost" approach to the Olympics.
Britain finished second in the medals table at the 2016 Rio Games with 27 gold medals and 67 in total.
UK Sport chair Katherine Grainger, a former rower and Britain's most decorated female Olympian with a gold and four silver medals, said the report was in part "a direct response to some of the challenges we saw last year."
UK Sport said it would invest a million pounds in an independent athletes' commission over the cycle to the 2020 Tokyo Summer Games as part of a range of initiatives.
The money, said the body which oversees the funding of elite sport in Britain, will allow the commission to triple its capacity to support members.
(Reporting by Alan Baldwin, editing by Ian Ransom)
