The idea for the movie came from a night Richard Linklater spent walking around Philadelphia with Amy, a woman he met. Contrary to the movie, they stayed in touch for a while, until contact was lost. Linklater never heard from her again, not even when he became a director and Before Sunrise (1995) was released. It was not for many years later that he found out that Amy had died in a traffic accident a few years after they had met.
Numerous references to James Joyce's novel "Ulysses" can be found in "Before Sunrise." Both take place on June 16th, running into the early hours of June 17th. Both involve a journey around a single city (Dublin/Vienna) and include a visit to a graveyard. Jesse's real name is James (Joyce's first name) and, like Joyce, he spent a long time wandering around the cities of Europe instead of going home.
In the scene where Jesse complains about fortune tellers never telling the truth, he quotes almost exactly from a scene in the book "The Circus of Dr. Lao" by Charles G. Finney. In the book the magician Appollonius of Tyana tells a widow that her next day and the day after will be exactly the same as the day before, "a tedious collection of hours". (Page 81, Grey Walls Press edition)
At the end of the film it is revealed that Jesse and Celine met on June 16th. This is the same date as in James Joyce's "Ulysses," which follows Leopold Bloom around Dublin for one day. June 16th is celebrated as "Bloomsday."