The chief of South Africa's military intelligence and four other senior officers were in Washington last week in what may have been a precedent-shattering visit, or may only have been a fluke. A somewhat embarrassed State Department, in guarded remarks yesterday, wouldn't say for sure.

U.S. policy, in keeping with the U.N.-sponsored arms embargo against South Africa, has prohibited visits here in recent years by senior South African military officers.

In large part the travel ban resulted from the sensitivities of black Africans about any suggestion of U.S.-South African military cooperation.

Spokesman David Passage, responding to press inquiries, said the five South African military officers had applied for U.S. visas in their home country as "government officials," without disclosing their military affiliation. The State Department is "reviewing the circumstances" in which the visas were granted, Passage said.

john M. Fisher, president of the American Security Council and host to the five South African officers, said "we are really in trouble if the U.S. Embassy in South Africa did not know who these people are." Fisher said he had notified the State Department by letter Feb. 27 of his intention to invite senior military intelligence officers, but did not receive a reply.

According to Fisher, the visiting South African officers included Lt. Gen. Van Der Westhuizen, chief of military intelligence; Admiral Willem N. duPlessis, who was defense attache in the South African Embassy here before being expelled in April 1979 in retaliation for expulsion of U.S. military attaches from Pretoria; Brigadier Gen. Nels Van Tonder and two others.

Fisher said the visitors had briefed American Security Council staff members on problems in southern Africa Tuesday and Wednesday.

According to the State Department, the visitors paid a "courtesy call" on the Defense Intelligence Agency and on an unidentified member of the staff of the National Security Council, but did not meet State Department officials.

U.S. policies toward South Africa are under review, with the expectation in many quarters that the Reagan administration will be much more cordial to that country than was the Carter administration. By sending the five officers, one source said, South Africa may be testing to see just how cordial the new administration will be.

The State Department spokesman said the department had been informed, when it inquired, that the visitors would be leaving last night. He did not say whether the State Department had taken any action to speed departure of the unexpected South African brass.