Is there a subdomain for each language?
Is there a "default" language that exists on the primary domain (i.e. English on www.yourwebsite.com)?
Are you using rel href lang, X-Default Hrefe Lang, rel canonical, or other "tags" or solutions for this at the moment?
If you could share the website address we wouldn't have to ask these questions, by the way. I know that is especially tough on client sites, but I just wanted to say that Dave has asked some vital questions, including the one about setting each subdomain as its own language / geographic target audience. Here is what he is asking about: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=62399
It is not necessary to have completely unique content for each language, as someone suggested below.