The Washington Redskins filled their top two defensive needs yesterday by trading next year's No. 1 draft choice to the Cincinnati Bengals for cornerback Lemar Parrish and defensive end Coy Bacon.

The two veteran NFL stars were disgruntled with the Bengals - Parrish reportedly because of contract hassles and because he did not like Cincinnati, and Bacon because Cincinnati intends to use the 3-4 defense exclusively this season. Bacon, who led the NFL, in quarterback sacks with 26 in 1976, had asked to be traded.

The deal, which means the Redskins will not have a No. 1 draft choice for the 11th straight year, gives the team a strong replacement for retired Pat Fischer and depth at cornerback, plus a player who should strengthen the pass rush considerably.

"It's not one of those trades that looks good on paper, and won't come true. It's immediate help," said General Manager Bobby Beathard.

"It's a big step for us, getting a couple of guys who have played that well," said Jack Pardee, the Redskins first-year coach. "The No. 1 pick is valuable. You hate to give one up. We were looking for more than one player who could help us right away. It had to be a multiple-player deal."

Parrish, 30, is an eight-year NFL veteran. He is a six-time AFC Pro Bowl selection. Both he and Pardee said yesterday that Parrish is the best cornerback in football.

Parrish is entering the option year of his Cincinnati contract, according to Beathard. The Redskin general manager said he spoke yesterday with Parrish and Rick Bennett, his agent, but "no offer is on the table." Beathard said he plans to meet here today with Bennett and hopes a contract can be worked out before the Redskins go to training camp July 16. Beathard would not discuss salary figures.

'I ought to be the highest paid cornerback in the game, a six-figure salary and I'm seeking that wherever I go," Parrish said. "The Bengals called me this morning. Ten minutes later I called the Washington Redskins to see when they wanted me to report."

"He wanted to get out of Cincinnati," Beathard said. "Sometimes negotiations go smoother with a player who wants to play here."

Parrish also is an established kick returner, although he returned only four punts for the Bengals last season.

Bacon, who will be 36 in August, is a 10-year NFL veteran and a three-time Pro Bowl selection. He played six years with the Los Angeles Rams and two with the San Diego Chargers before joining the Bengals in 1976, the year he led the league in sacks. Bacon was playing in a golf tournament yesterday and could not be reached for comment.

"Coy Bacon will be able to help us too," said Parrish. "I don't know what his problems were. But I know he run play football, I'm a witness to that."

Parrish is expected to replace Gerard Williams as the starting left cornerback and Bacon will be seeking to dislodge Dennis Johnson as the starting right end.

Pardee, of course, would not concede starting Jobs to the newcomers yesterday. He said: "We're going to have competition and a good team with some depth . . . when you get good players, you find a way to use them, and a lot of things can happen during the year - it's in the Lord's hands."

The Redskins had been reduced to two veteran cornerbacks going to training camp next month at Carlisle, Pa., since 17-year veteran Fischer could not pass a physical examination after undergoing back surgery last season.

Finding another cornerback had been Pardee's chief priority.

"If you're having trouble at a spot, you don't look for a guy you can get by with, but you look for the best," Pardee said. "I consider Parrish the premier cornerback in the league and I think he has four to six years left."

Bacon gives the Redskins the true outside rush man they have lacked, according to Pardee, and also depth. Tackle Bill Brundidge is a doubtful player this season because of a lingering ankle injury.

"Bacon's a big strong man who can rush the passer," Beathard said. "He played hurt a lot of last year. He has a history of following up a trade with a couple of outstanding years. It's a shot in the arm for us and, I think, for Coy, too."

Beathard said Bengal General Manager Paul Brown told him Bacon did not fit into Cincinnati's plans this year.

"They drafted two defensive linemen in the first round last year and two more this year," Beathard said. "It's a position they felt they had an excess at, and they might as well trade the one who wasn't happy, and that's what they did."

Pardee said the Redskins were still seeking to improve themselves offensively, especially in the line, but that no trade was imminent and the free agent route seemed the best way at this time. He said he would like to have all personnel changes made prior to training camp.

Beathard said no trade was in the works for quarterback Billy Kilmer, who wants a multiyear, guaranteed contract. "As far as we're concerned, Billy will be a Redskin this season," he said.

Kilmer currently is out of town and unavailable for comment. Before he left, there were reports that he and the Redskins were close to agreeing to terms. Kilmer is entering the option year of his contract. His salary is estimated at $200,000.

Reminded that George Allen traded away Washington's high draft choices because "the future is now," Pardee said: "It's today, tomorrow and all the way down the line if you're doing things right."