My fiancée and I are not married yet. How can my fiancé get a visa to enter U.S. to get married with me?

Answer:

A K-1 visa or fiancée visa gives permission for an foreign fiancée or fiancé to enter U.S. to get married. To get a K-1 visa, the U.S. citizen needs to file a K-1 visa application with Form I-129F to the USCIS (U.S. Citizenship and Immigration Services). If the Form I-129F is approved by USCIS, the documents will be forwarded to the U.S. consulate in the foreign fiancée's / fiancé's home country for review. An interview with the K-1 applicant will be scheduled to take place at the U.S. consulate. A K-1 visa will be issued if the interview goes well.

After the K-1 visa is issued, the fiancée or fiancé has 6 months to enter the United States, and then have another 90 days to get married in the United States. If the foreign fiancée/fiancé wants to get a U.S. Green Card (adjusting status in U.S.), the official government issued marriage certificate is needed to submit the Form I-485 application - adjustment of status.

http://www.greencardfamily.com/question/question2014/K1_Fiance_Visa_0421.htm