At the beginning of the film, Peter is seen entering a large stone building with "Policia Nacional Jefatura" engraved over the entrance - which translates as "National Police Headquarters". It was the actual building at the time. Since the Castro revolution, the entryway has been re-engraved "Policia Nacional Revolucionaria Comandancia General".

Palinov's fee of $1,000 to smuggle someone into the United States would be the equivalent of nearly $10,000 in 2016.

The tail number of James' dummy plane, NC54860, was an actual number assigned to a North American AT-6B owned by MGM at the time. The actual smuggling plane, marked NC80356, was in reality used on a 1946 Beech D-18S bought by MGM for use by Robert Taylor and his wife Barbara Stanwyck. Taylor named that plane "Missy" - his nickname for Stanwyck.

Feature film debut of Steven Hill.

At the beginning of the film is seen the S.S. Joseph R. Parrot, a railroad car ferry that ran between Havana and Palm Beach, Florida, and was owned by the West India Fruit and Steamship Company. Built in 1916, she was requisitioned by the U.S. Navy in 1942 and renamed the U.S.S. Salem (CM-11), serving as a mine-layer and submarine net layer. She served in the Mediterannean and Pacific theaters earning two battle stars. She returned to commercial service in 1947 and ran the ferry car route until it was discontinued c.1960 due to the Cuban revolution. Sold to a Honduran firm for use as a cargo ship, she was scrapped in 1970.

Robert Osterloh also plays an INS agent in the film Illegal Entry (1949)