What areas should you avoid in Paris?

It's not like the big cities in the USA. There is not really any crime. You can even feel safe walking around at night but very few Taxis run after midnight. the City is safe but do not venture to the suburbs

I live in Paris. The only friend of mine who got problems once (somebody stole her bag and break her arm) was living in the 16th arrondissement, which is the most exepsive place of Paris... If you avoid the places like Saint Denis, La Courneuve, Mantes la Jolie... Well, you'll have no problem at all. Paris is a safe city. I often come back to my appartment after 11pm, and I feel very safe.

I guess the banlieues during the riots. But I think that you should just be aware in high-tourism areas.

Even if I don't agree with Rillifane's explanation of the reasons for the situation in the suburbs: in general he is right - I don't mind the points... ;) The only thing you should be aware of are the (very "professional") pick-pockets, not only in the touristy areas, but also everywhere and everytime in the public means of transport (which are always very safe - alarms everywhere and an very dedicated & experienced staff which knows how to act towards idiots). Parisians are very aware of the pick-pockets and sometimes even warn others when these have left their bags opened! As Rilli already mentioned, you should (to some extent) be careful around Châtelet area (Les Halles at night isn't fun, the streets around the Centre Pompidou aren't that dangerous - only gays and prostitutes) and at the Seine banks at night. Montmartre and St-Denis can get really scary at nights, but in the evenings you just have to care about your credit card and your camera. And the area around the train stations are somehow bizarre at night... As in every other city in the world! (^_^) But, hey! Relax and enjoy your stay! Have great time!

suburbs are dangerous

The Barbes boulevard area, and the Forum des Halles are two places that is better to avoid at night, even if it's true that Paris is safe globally. You should contact the US consulate to get a precise picture. http://www.amb-usa.fr/ Or take a look at the official Paris council web page http://www.v1.paris.fr/EN/