Reagan administration political adviser Edward Rollins suffered "a slight stroke" and is in stable condition at George Washington University Hospital, White House chief of staff James A. Baker III said yesterday.

Baker said he had been told by neurosurgeon Arthur I. Kobrine that Rollins had suffered a slightly blocked artery in his neck and that his prognosis for complete recovery was "excellent to good."

Rollins, 39, who succeeded Lyn Nofziger as assistant for political affairs, was rushed by ambulance to the hospital Monday night after complaining of a pain in his left side while working in his office. It was announced originally that Rollins, who also has ulcers, had been hospitalized for coronary observation.

The bearded, outspoken Rollins, known as a hard worker, had been keeping especially long hours in the final weeks of the midterm election campaign, aides said. When he was first able to speak several hours after being taken to the hospital, he told aides he wanted to return to work.

Nofziger also suffered a stroke, from which he has recovered, a few months after leaving the post taken over by Rollins, his friend and former deputy.

"I can't even get my own sickness," Rollins was quoted as saying by his assistant, Michelle Davis.

White House press secretary James S. Brady, who is recuperating from the severe wounds he received during the attempt on President Reagan's life last year, visited Rollins at the hospital yesterday. Baker said that the president had put in a call to Rollins and that the political aide would return it when he recuperates more fully.

Rollins was in isolation yesterday and listed by the hospital as in "fair and stable condition." He is expected to remain hospitalized for several days.