The Prince George's County Detention Center, plagued in recent years by frequent sexual assaults among male inmates, overcrowding and allegations of mismanagement, was given high marks, in a state audit released yesterday, for correcting most of those problems.

While auditors noted that the jail is still overcrowded, they found the Upper Marlboro facility "well managed with efficient, effective and motivated staff."

The annual audit, conducted this summer and fall by the Maryland Commission on Correctional Standards, said the county facility was in compliance with most of the standard criteria and that "most of the identified deficiencies are minor in nature and will be addressed in the near future."

The auditors also found inmate morale to be "good with only minor complaints."

The audit cites eight deficiencies at the jail, including procedures to deal with inmate medication and emergency evacuation plans. It noted that the facility has no provision for housing inmates in case of mass evacuation.

The jail staff said yesterday that three of the problems had already been corrected since the audit was conducted and noted that one of the deficiencies is being remedied with the current installation of a smoke-detection system.

The audit was the first since Samuel F. Saxton took over the county's troubled corrections department last year. Saxton's predecessor, Arnett Gaston, resigned in the spring of 1983 during controversy over charges of mismanagement as well as an escape and a Washington Post series that detailed the sexual assaults, estimated at as many as 12 a week.

By comparison, Saxton's tenure has been uneventful. While the jail is still the scene of fights among inmates and other problems related to its design and size, many officials involved with the jail say Saxton is generally held in high regard.

"He's the best thing that's happened to this county," said Con Siland, assistant sheriff for court operations.

Circuit Court Judge Howard Chasanow said allegations of sexual assaults and other complaints about the jail have declined. "The jail's the kind of place where no news is good news," he said.

County Executive Parris N. Glendening, who released the audit at a press conference yesterday, said he was pleased at the jail's "tremendous success story" since his appointment of Saxton.

The jail, Glendening said, had been "an absolute disgrace" and a "nationally known insult" to the county. But "any jail in the world would be happy to receive this kind of evaluation," he said of the audit.

The 1983 audit found 10 deficiencies including inadequate staff training.

Saxton's success appears to be largely related to his management style. A tough-talking ex-marine, he has upgraded staff training, conducted surveys to measure staff and inmate morale and improved reporting of security problems.

The audit indicates that the jail's most serious problems can be attributed to its size and design rather than management or staffing. The facility is designed to hold 398 male inmates and 24 females. The audit reports an average daily population of 465, down 6 percent from 1983.

"However, the average population has continued to exceed the maximum capacity," the audit states.

A $29 million jail designed to hold about 600 inmates is scheduled for completion in 1986.