Two months into their marriage, Andrew Motiwalla and his wife had only a futon mattress to their name and an entire unfurnished house to decorate. And so the blissful couple set out from New Rochelle to the 350,000-square-foot Ikea in Elizabeth, N.J., eager to acquire the trappings of their new life together.

But by the end of the day, Mr. Motiwalla had been reduced to a cursing, furniture-throwing wreck in front of his new bride. While trying to assemble the chairs they had lugged home, Mr. Motiwalla was screaming in frustration – “I hate this! I hate this! I hate this!” – while his wife pleaded for him to calm down. The couple had to hire a carpenter to assemble the furniture for them. “There’s probably some equivalent to road rage in the furniture world,” Mr. Motiwalla said recently, “and I experienced that.”

Ikea offers good design, extremely low prices, and easy-to-navigate stores. But there’s a catch: For couples, a trip to the megastore can often wind up in a fight.

For New York couples without cars, going to Ikea entails renting a car or climbing aboard the shuttle bus that runs between Port Authority and the Elizabeth store. But on top of the expense of a rental or the annoyance of the bus, a trip to Ikea often accompanies a step into adulthood. Many shoppers are moving in with their significant other for the first time, which brings along some implicit stress. A trek to the store also means getting up early, roaming the floor for hours, eating meatballs cafeteria-style, choosing one kitchen table out of a cast of 40, and realizing for the first time that you favor dark wood while the gentleman prefers blond. Can this relationship be saved?

For some, the trouble starts as soon as they arrive at the store. A 26-year-old Web designer who declined to be named said that when she went shopping with her girlfriend for their apartment, she almost immediately wanted to leave. “Ten or 15 minutes in, I just panicked,” she said. Experiencing something like a minor anxiety attack after seeing the crowds at the store, she told her girlfriend that she had to go.

Her girlfriend called her bluff, saying, “Okay then, leave.” The designer promptly took their borrowed car and drove home, leaving her girlfriend there to shop for several more hours. Her girlfriend bought what they needed and took the shuttle bus back to Manhattan. When she finally made it home, the reunion was not, needless to say, a happy one.

The couple reconciled, eventually returning to Ikea together to furnish their next apartment. But the designer still shudders at the memory. “Putting yourself through that much mental anguish to get a cheap bookcase just didn’t seem worth it to me,” she said.

“I know people who do love it, which I don’t understand,” she added. “But I also don’t understand people who like eating in cafeterias.”

For others, the tension hits when they load up their cars – or the undercarriage of the shuttle bus – with stacks of flat-packed furniture and plastic bags of cheap lamps and wine glasses and head back home. That’s when the assembly begins. Unlike Mr. Motiwalla, most shoppers manage to assemble the furniture without paid help.

An Ikea spokesman, Clive Cashman, acknowledged that the store can be a trigger for unrest. “The home is close to the heart, so there’s bound to be some issues that come up,” he said. “It’s our job to make it hopefully as enjoyable as possible.”

Ikea playfully acknowledged one style of in-store fighting in its 2002 “Unboring” television ad campaign, directed by Wes Anderson. In the first spot, a couple fights in a kitchen: The wife bitterly complains that she is “stuck in here like some prisoner” and accuses her husband of “prowling the streets.” But in fact, they’re in a mock kitchen at Ikea, testing out the room for home use.

Similarly, many of the actual fights that take place in the store reflect the larger issues behind the rugs and tables that seem to cause them. Don Ferguson, a Wisconsin psychologist whose book, “Reptiles in Love: Ending Destructive Fights and Evolving Toward More Loving Relationships” (forthcoming in February from Jossey-Bass) said that couples may be struggling with different issues during their shopping trip.

“There are so many implicit choices,” he said. “You’ve got dollar issues. You’ve got ‘Am I doing the right thing by moving in with this person?’ Or am I just hungry? Do I need to go up and get some Swedish meatballs?'”

He advises that couples avoid fighting by planning ahead. “Build a framework of predictability so you’re not making too many guesses,” he said. “The reptilian brain needs structure and predictability. That goes against, ‘We’re just having fun and we’ll shop ’til we drop.'”

Ikea suggests the same thing. Mr. Cashman said that one way to manage conflicts is to use the company’s catalog and Web site to make some decisions ahead of time. “If you’re planning a space, it’s great to take your measurements with you. You’ll be equipped to say, ‘That will work,'” he said.

Next year, New York City couples will see one stressful element of the Ikea trek eliminated: Ikea will open a store in Red Hook in the summer of 2007. Instead of the shuttle bus, New Yorkers can ride the B-61, whose route will be extended to end to the store’s doorstep. There will also be a free ferry from Lower Manhattan and shuttles from several spots in Brooklyn. “Brooklyn’s going to be really busy,” the director of public affairs for Ikea North America, Joe Roth, said. “Bringing the experience closer makes it easier for customers in Brooklyn and it makes it more pleasurable for customers in Elizabeth,” which will become much less crowded.

Mr. Motiwalla’s story, at least, has a happy ending. He and his wife returned to the store two months ago when they found out she was pregnant, choosing and assembling a new crib without incident. “We took pictures of ourselves building the furniture so we can show it to the baby someday,” he said. “It became a fun task.”