Georgetown haidresser Raymond Louis Urgo pitched quarters against an Arlington courthouse wall in a game he played Saturday night with one of his attorneys and a reporter.

Urgo joked that he wasn't playing the game well because he was wearing his Yves St. Laurent suit. He was passing the time until a Circuit Court jury early Sunday found him guilty of involuntary manslaughter in the shooting death of his girl friend, Ellen Dana Kisacky, at a sex and drug party in his Arlington apartment last January.

The jury sentenced Urgo to the maximum penalty of five years in prison. But Circuit Court Judge Charles S. Russell postponed imposing the sentence until a presentence report on Urgo is presented Aug. 18.

When the verdict was read at 12:50 a.m. yesterday, Urgo sat motionless. As he left the courtroom his mother, who lives in New York, cousins and friends hugged him and shook his hand. Urgo, smiling, appeared drained after waiting 8 1/2 hours in the courthouse for the jury to reach its verdict. But Urgo also seemed relieved and pleased that the jury had rejected a prosecutor's request for a second-degree murder conviction.

The jury also found Urgo innocent of the charge of using a fireman during the commission of a murder. The verdict was automatic since the jury did not find Urgo guilty of murder.

Assistant Arlington Commonwealth's Attorney William A. Nun III asked that Urgo be placed in jail since he was found guilty. But Russell allowed Urgo to remain free on $20,000 bond.

Numm said he thought the jury's verdict "was certainly adequate based on the evidence. Once it goes to the jury, they have to call it the way they see it. I think it was a tough one for them."

Jurors in the case said they had agreed not to discuss their verdict with reporters.

Urgo was accused of shooting Miss Kisacky in the mouth with his .357 magnum revolver after he, Miss Kisacky, and two other women engage in group sex, drank wine, took Quaaludes and smoked marijuana at his Arlington Towers apartment Jan. 8.

During the five days of testimony prosecutors introduced evidence that Urgo had previously used marijuana, cocaine, heroin and Quaaludes, a calming drug used to enhance sexual pleasure.They also suggested that Urgo engaged in unusual sexual practices using guns, chains and handcuffs.

Urgo contended that the shooting was an accident, that he did not intend to kill Miss Kisacky, who was living with him. But he said he wanted to "add realism" to the party and impress the women, according to his statement to police. He did not testify at the trial.

In a taped interview with police hours after the shooting, Urgo said he, Miss Kisacky and the two other women had taken drugs and engaged in sexual activities when he decided to load five of six chambers in his revolver and scare the women. Urgo said he checked to make sure the empty chamber, not a live bullet, would fire when he pulled the trigger.

While Miss Kisacky and the other two women lay on Urgo's bed kissing, Urgo said he held the gun to Miss Kisacky's lips and pulled the trigger, killing her instantly.

One of the women at the party, Mary Kingsley of Arlington, said, Urgo stood "frozen . . . absolutely ashen" as blood spurted from Miss Kisacky's mouth. The women jumped from the bed and fled half dressed from Urgo's apartment as he called police, Miss Kingsley testified.

In his closing argument Assistant Arlington Commonwealth's Attorney Arthur L. Karp said that Urgo was "using the gun to play sex games," that Urgo had been left sexually unsatisfied and "decided to use the gun to get himself into action."