An affidavit is a sworn statement of fact that can be used in a variety of legal proceedings, from bankruptcy cases to family and civil litigation matters. An affidavit is the written equivalent of verballygiven court testimony.An affidavit is a written statement made under oath or affirmation. It's used as evidence in legal proceedings. An affidavit is a type of verified statement or showing, or containing a verification, meaning it is made under oath on penalty of perjury. USCIS.gov now has an online dictionary (glossary). You can use this dictionary to quickly look up a definition or explanation for a topic. Visa Waiver Program, Fraud Warning, Find a US Embassy or Consulate, Straight Facts on US Visas An affidavit is a legally binding document that is used to present written sworn statements or facts.