Filmed in 23 days because the creators had rushed post-production so it would be finished in time for Sundance. Even though it was admitted after the deadline, the movie became one of the breakout hits of the festival.
Jules (Julianne Moore) has a tattoo on her left wrist that reads JLN. This stands either for "Jules Loves Nic" or "Joni Laser Nic". The ink can most easily be seen about twenty minutes into the film when Jules and Nic are watching "Locked Up Abroad."
Although this movie only played in 7 theaters during its first weekend of North American release (3 in New York City and 1 each in San Francisco, Chicago, Toronto, and Los Angeles), in terms of per-screen average, it was the box-office winner for the weekend.
When Jules is trying, awkwardly, to explain the reasons that lesbians might prefer to watch gay male pornography rather than porn showing two women together, one of the reasons she gives is that they always cast two straight women pretending to be gay in those movies. Both Julianne Moore, who plays Jules, and Annette Bening, who plays Nic, are in their real lives straight actress pretending to be lesbians for this movie.
The film has four references to wineries that appear prominently in Sideways (2004). During the first family dinner scene, the label of the wine bottle on the table is Frass Canyon; Nic looks at it and asks Jules if there is any more Fiddlehead. Frass Canyon is the contrived name of the winery where Paul Giamatti's character in Sideways (Miles) drinks from the spittoon and then dumps the remaining liquid on his head. Miles and Virginia Madsen's character in Sideways (Maya) rave about the Fiddlehead Sauvignon Blanc that Maya is drinking when the two couples meet for dinner--immediately following the famous Merlot scene. When Paul visits Jules and Nic's home for the first time, he announces that he's brought a bottle of Petite Sirah; the label is from Kalyra, the winery where Sandra Oh's character in Sideways works and meets Jack (Thomas Haden Church). Just before the scene when Nic learns of Jules's affair, Paul excitedly tells Nic that he has a "killer" bottle of Alma Rosa Pinot Noir (and the Alma Rosa label appears on the bottle). Alma Rosa is the winery owned by Richard Sanford. At the time Sideways was filmed, Richard Sanford owned Sanford, the first winery stop for Miles and Jack where Miles waxes poetic about Sanford's Pinot Noir. Alma Rosa's tasting room was the Sanford tasting room that appeared in Sideways, and Chris Burroughs, the wine pourer at Sanford in the film, poured for Alma Rosa as recently as 2014.