The group said antagonism between Rakhine Buddhists and Rohingya Muslims had led to threats that have prevented it from providing health care for tens of thousands of people from both religions.
"It is outrageous that doctors are not allowed to carry out their duties providing care for those that need it," including some in life-threatening conditions, said the group's operations manager for Myanmar, Joe Belliveau.
The government said last week that 89 people were killed, 136 were injured and more than 32,000 made homeless in communal violence in Rakhine state last month in which more than 5,000 houses were burned down. Similar violence in June left about 90 people dead and 75,000 homeless.
Tensions remain high, with many Rakhine Buddhists calling for the segregation or expulsion of the Rohingya, and criticizing agencies that provide them with aid.
Doctors Without Borders said the tensions prevented it from helping people displaced by the crisis as well as others in need of normal clinical care.
Because of the threats, many of the group's staff are unwilling to carry out their work, "even though what we are doing is simply providing medical aid, and is in no way involved in the political situation," Belliveau said by phone from the Netherlands.
He said those hindering the group's work were "a small majority but a very vocal one." The threats were transmitted through letters, in person, on Facebook postings, and on some posters and pamphlets in the Rakhine state capital of Sittwe, he said.
The group, also known as Medecins Sans Frontieres, has worked in Rakhine state since 1994.
Belliveau said the critical moment came last week when the group tried unsuccessfully to reopen a clinic in a primarily Rakhine neighborhood that provides basic health care as well as care for HIV patients. Some protesters carried posters saying "No to MSF" and some doctors were directly threatened, he said. The group had hoped to reopen several such clinics.