Hello I recently got married and was thinking to file for my spouse, However, he has told me that 8 years ago he went to Canada under bogus documents, was caught and returned home. Charges were not pressed against him. Do you suppose this will be a problem for him in immigrating o the US if I go ahead with filing?

Yes, it will be a serious issue, and although charges was not filed, she was sent out for having documents that were fraud. You should be using a immigration attorney on this. Where is she living now? And if in the US on what visa?

Yes, and no. This record may jeopardize his case but if it is misdemeanor and it happened long time ago, so such offense occurred in the past 5 years, he will be OK but he needs to disclose all information, do not lie ever!!