On a recent shopping trip to Barneys New York, Jessica Meli spent $170 on two pairs of designer jeans by Diesel -- one with oversized pockets, the other with a medium-blue finish. The recipient? Her 21-month-old son.

"Compared to other jeans, these don't make him look like he has a full diaper," says Mrs. Meli.

Jean-mania is trickling down -- to the 2T, 3T and 4T set. Fashion-conscious parents are increasingly spending adult prices on denim for toddlers. These jeans even sport adult-like detailing, such as "whiskers" (distressed horizontal lines) in the lap area, to distressed spots and studs on the upper thigh and lower leg.

Lucy Sykes New York, which introduced $93 toddler jeans made from vintage wash denim last January, doubled production for this spring. Genius Jones, a kid's boutique in Miami, tripled its stock of designer jeans this spring (price range $98 to $135) and says the new lines, including jeans with copper rivets and double stitching from Lit'l Earnie, are selling briskly. Barneys New York launched pint-sized $110 Paper, Denim & Cloth jeans in 2002; today, the line makes up 20% of the store's toddler apparel sales, according to Tracy Edwards, a merchandise manager for the store. "It's the fastest-growing section of the children's business for the past 18 months," says Ms. Edwards.

Although there's nothing new about pricey kid's clothes, parents traditionally have splurged on special-occasion outfits, such as Ralph Lauren sport coats. For more casual wear, they tended to shop at such chain stores as Gymboree and The Gap, where jeans start at about $20.

In general, toddler denim is selling so well, it's contributing to the revival of the children's clothing market. Though sales in the children's-apparel industry dropped 5% in 2004, they rose 2% to $27 billion last year, thanks in part to a 5% jump in sales of all kid's jeans, says market-research firm NPD Group. A majority of that growth is coming from pricey denim. "We really do want our children to be a reflection of who we are," says Marshal Cohen, NPD's chief retail analyst.

Well, not everyone. Kristen Foodim, a New York mom, buys herself jeans from labels such as Seven for All Mankind (about $175 a pair) but draws the line at buying jeans for her 2-year-old son. "I like the way they fit," she says of pricey toddler denims. "But it's not like my son has issues with his body type yet."

Nor does junior appreciate his $100 jeans. Jennifer Lattuca, a mom in Dixville, N.Y., was horrified when her 2-year-old daughter drew on her $106 True Religion jeans with permanent markers. "She only wore them a couple of times," says Mrs. Lattuca. After the incident, she vowed never to spend more than $40 on a pair of kid's jeans.

Still, designers are rolling out a new array of child-size denim this spring. Seven for All Mankind and Lit'l Earnie are introducing skinny-leg jeans, and Paper, Denim & Cloth is expanding its kid's line with two new washes. Kelly Gold, a mom in Miami Beach, Fla., says she's already asked the sales people at her favorite stores to call when new shipments arrive, so she can outfit her 3-year-old. "This is definitely a fashion victim child," she says. "Sometimes I think, where do we draw the line?"