Not since the King Tut exhibition in 1978-79 have the ticket lines been so long.

The show doesn't even start until May 22 but already New York's Museum of Modern Art is selling a maximum 4,000 tickets for each day of the exhibit "Pablo Picasso: A Retrospective," the most comprehensive collection of Picasso art ever assembled.

Museums officials predict attendance will surpass the half-million for the Cezanne exhibit in 1977-78. Almost 80,000 tickets of a possible 800,000 available to the public have already been sold for the May 22-to-Sept. 16 exhibition. In all, about 1 million are expected to see the show.

In Washington, and around the country, tickets are available through Ticketron. At lunch hour yesterday at Ticketron's 17th Street NW location, only about a dozen persons were lined up for tickets of all sorts. "I just got two," beamed one woman who had bought Picasso tickets and avoided the crush in New York.

Prices have not eased that crush. Admission rates are $4.50 for adults, $2.50 for students with identification and 75 cents for children 16 and under and for senior citizens. Each ticket purchased at Ticketron carries an additional 75-cent service charge.

All week, lines have strung out along 53rd Street and wrapped around St. Thomas' Episcopal Church on Fifth Avenue, where weary Picasso fans sit on the stone steps.

"Agnes, maybe we should go in and pray for tickets, said Charlie Patten to his wife as they sat there the other day.

"We have been selling to our capacity here everyday," said James Synder, the Museum of Modern Art's coordinator of planning. "It has been surprisingly heavy for the first week -- heavier than we expected.

"When we had Cezanne here, we simply had admission at the door. But the galleries became so crowded it became an unpleasant situation. We felt by selling tickets in advance for Picasso, we would be able to avoid unpleasant congestion in the gallery."

Many of those waiting in line compared interest in the Picasso show with the King Tut exhibition, which drew more than 1,300,000 at the Metropolitan Museum of Art in 1978-79. "I waited in line there for 10 hours -- in the rain," said Margaret Simpson, who was on her lunch break while waiting for Picasso tickets.

Many who waited read books, magazines and newspapers while others brought lunches, radios, collapsible chairs and, in one case, overdue income tax forms.

"I got an extension," explained Harold Carson to a group of curious New Yorkers.

Inside the museum's lobby, security guards ushered groups of two and threes who had been waiting outside to yet another line inside.

"I though this exhibition was the beginning of my divorce," said Suzanne Gyorgy, who supervises the lobby bookstore and whose husband, Tom McLaughlin, manages the entire lobby. "His whole life lately has been taken over by Ticketron and Picasso. Our nerves are already frayed."

Seventy - four - year - ole Florence Weissman said she was happy to stand in line. "We did it at the Met for King Tut, so we figure we can do it here for Picasso," said Weissman. "We're New Yorkers and we like to seen anything that comes to our town."

David Pascal, a 60-year-old cartoonist whose work appears regularly in the New Yorker and other publications, missed the Picasso exhibition while in Paris but is determined to see it in New York.

"Only for Picasso would I do this," said Pascal, who commented that Picasso was "really the greatest cartoonist ever. He never lost sight of people. Many artists become abstract and certainly some of his work did, but there was always that recognizably human element."

Looking at the long line, hemmed in by white ribbon and steel stakes, Pascal was reminded of the story of when Picasso once visited a friend in a lilac garden and was so moved that he rushed home to his studio to paint a purple canvas.

"He had to get it out of him," said Pascal. "If he was alive today and saw these people in a scene like this, he might feel the same way. But I doubt it. Picasso never was one to, how do you day, partake of the scene."