The 51-year-old was convicted of two counts of being an accomplice to rape related to a marriage he conducted in 2001 between Elissa Wall, who was 14, and Allen Steed, 19.
The first rape count occurred between April 23, 2001 -- the day Jeffs conducted Wall's marriage -- and May 12, 2001, when she and Steed took a trip to Canada to visit her sisters.
The second count occurred between May 13, 2001, and Sept. 30, 2003.
Sentencing is scheduled for Nov. 20 at 1:30 p.m. Asked if he wanted a pre-sentencing report completed, Jeffs answered that he would do what his attorneys advised.
A pre-sentencing report gives the judge further information about a defendant. Jeffs' attorneys requested the report, and said they would also file a sentencing memorandum.
The three-member defense team walked out of the courtroom shortly after 2:30 p.m., and lead attorney Walter Bugden said only, "Of course we're disappointed."
A 5th District jury of five men and three women had deliberated about three hours today with a new member. One of the eight jurors was excused this morning for a reason that was not disclosed. She was replaced with a woman who was one of four alternates. The original jury had deliberated for about 13 hours.
University of Utah law associate professor Daniel Medwed said he was "mildly surprised" at the verdict. He said he thought the facts of the case were not a perfect fit for the charges, and that lesser charges - possibly solemnizing an illegal marriage - might have been more appropriate.
"Feeling he had done something wrong is a little bit of a stretch to saying he was an accomplice to rape," Medwed said.
He also said that even if Jeffs comes before the parole board, it will be a long time before he's released.
"I would be quite surprised if Jeffs ever got out," he said.
Medwed also said the defense might appeal on grounds of insufficient evidence, but that is historically a difficult appeal to win in Utah.
Sam Brower, Cedar City private investigator who has assisted state authorities in building cases against Jeffs, said after the verdict: "It's a good day. It's a good move. I think the jury did a great job of sifting through all the evidence. Jeffs can't say he didn't get a fair trial."
Elaine Tyler of the Hope Organization, a group that opposes forced marriages in polygamist communities, said she hopes the verdict will prevent young women from being told to marry against their wishes.
"It represents hopefully a change in that polygamist community," she said.
Attorney General Mark Shurtleff Shurtleff reacted to the verdict in a telephone call from his hospital bed in Salt Lake City. "It sends a message to all the other victims of Warren Jeffs that there's justice," he said, referring to underage women who have been married to older men.
Shurtleff maintains some FLDS followers will stick by Jeffs, but others will move to replace him and move away from child-bride marriages.
He said some concerns remain about the FLDS, and that the biggest one is getting children an education, considering many are pulled out of school at an early age.
Arizona Attorney General Terry Goddard, who has pending, similar cases against Jeffs, said the verdict made history.
"I commend the jury for carefully reviewing the facts and rendering a fair verdict," Goddard said in a written statement. He added that the case was not about religious beliefs "but about protecting young women from being abused."
In Mohave County, Ariz., Jeffs is charged with eight counts related to two teen brides. One of the brides is Elissa Wall.
"It is too early to speculate on what will happen next," said Mohave County Attorney Matthew J. Smith. "The first thing we need to see is what type of sentence Warren Jeffs receives in Utah. That may determine what happens next. The second question then is whether or not he will go to Arizona or the federal authorities will get him, although it seems likely that he will probably go to Arizona first. The final question will be what are the desires of the victim, which may be somewhat determined by what happens to Mr. Jeffs in Utah. Other than that, any answers on what is going to happen next would be pure speculation."