After being in business for almost 200 years, the classic clothier will launch the collection, called "Fleece," at 15 stores in the U.S. and three internationally for Fall 2010.
It is being designed by children's wear designer Nikki Kule, who is best known for her own namesake line "Kule."
"It's for girls, ages 4 to 12 and it's got all the elements of what girls would wear for school, play, weekend and parties, plus shoes and accessories," Kule told StyleList.
The girls' pieces took a bit of time to figure out. "There is no archive of girl's wear so we gave birth to this collection -- it was created from scratch with the Brooks Brothers look and feel," Kule explained.
"There is one T-shirt which is the lynch-pin for the collection. It says 'I Love My Brother.' This collection is the sister to the boys' collection and it is what she would look like in clothes inspired by him."
There are navy blazers, Oxford shirts, stripes and plaids. "I love the Brooks Brothers look, but this is more than that," Kule told us. "It has a modern twist and is not straight up classic. It's for today's kids in this modern world."
Prices start at just under $50 for casual pieces and will range up to around $198 for outerwear pieces.
The partnership came about exactly one year ago, when Kule met Claudio Del Vecchio, Brooks Brothers' Chief Executive Officer, at the 2009 Financo CEO cocktail party.
"He was on the panel, talking about starting a kids collection," she said. "I spoke to him and he said send over what you do. After lots of meetings it really seemed like a natural fit."
The boy's collection is also expanding to include more active sportswear pieces, with help from Kule, starting this spring.
Kule is the second designer Brooks Brothers has collaborated with. Menswear designer Thom Browne has designed the Black Fleece line since Fall 2007.