Internship interview-what do i wear??

You might want to dress up and formal since they are a clothing company. no jeans unless you are a model looking for a runway show or someone looking for waitress jobs
 
It's a job interview (even if you don't get paid), if you want the internship you should dress up. Look professional, and clean. Chic casual is ok if you are student, meaning a clean solid color sweater, a pair of solid color non stretchy pants and flats.

No jeans, no camisoles or boob tubes, no minis, too much make up and perfume, no Laura Ashley dresses with tiny flowers, no Doc Martins boots, no toes peeking, no wild manicure (better go natural or with a nude polish, even french is not always appreciated), no piercings in the face, no fishnets, no bangles in the wrists that make sound, no Jamaican inspired tshirts, band tshirts, love bears tshirts, no sneakers, no juicy track suits.

I think I mentioned everything women have worn in job interviews, in our office when I was looking for a temp assistant.
 
No jeans, no camisoles or boob tubes, no minis, too much make up and perfume, no Laura Ashley dresses with tiny flowers, no Doc Martins boots, no toes peeking, no wild manicure (better go natural or with a nude polish, even french is not always appreciated), no piercings in the face, no fishnets, no bangles in the wrists that make sound, no Jamaican inspired tshirts, band tshirts, love bears tshirts, no sneakers, no juicy track suits.

I think I mentioned everything women have worn in job interviews, in our office when I was looking for a temp assistant.

OMG seriously?!?!?! Who wears a boob tube (or a Juicy tracksuit/band shirt etc) to an interview LOL, especially in an office!

OP, Liliy25 has given you great advice (as have the others, of course!). This is an interview, you can be more relaxed after you have the job, but it's better to be safe and professional for the interview. Your appearance says a lot about your work ethic and your ability to make good judgements - these non-verbal messages are often deal breakers/makers!
 
Even though its a fashion company, I wouldn't wear jeans. You have to look fashionable, but not like you are out shopping all day. A dress with tights, or trousers with a blouse, it's better to be over dressed rather than under dressed.
 
I agree, jeans are not a good idea. I think since it is a fashion house, you need to look sharp but still 'interview-appropriate'. I'd wear great black pants and a top with a little scarf or embellished detail just visible under a well-cut jacket. Good shoes and good bag. An outfit that implies your fashion-rep, rather than screams it from the rafters!