You will be required to submit to the Administrative Unit:
Both spouses' original birth certificates or certified copies, affixed with an apostille.
Both spouses' passports.
A Free to Marry Certificate for each spouse, also known as the Certificate of No Legal Imediments. Since no equivalent document is available from the United States, American citizens may come to the Embassy and swear/affirm an affidavit stating that they are currently single and free to marry. This is a routine notarial service for the American Citizen Services Unit, and costs $50. We have a form prepared for this, and the Slovene authorities accept it for this purpose.
If either party has previously been married, then you must provide the original death certificate of the former spouse or the original final divorce decree, in order to prove the termination of the previous marriage(s).
All documents not in Slovene must be accompanied by a translation performed by a certified translator.
For further information please see the Slovenian Embassy website below - http://slovenia.usembassy.gov/getting_married.html