The ambient noise level aboard the ship was increased in the alternate time-line. Consoles and displays were made more audible, the warp engines made a dull roar sound, intra-ship communication announcements increased, the doors made a "swoosh" sound reminiscent of the sound effect used in the original Star Trek (1966) series. Set lighting was also significantly changed and darkened.
In the alternate time-line, this episode's story writer Trent Christopher Ganino's name can be seen on a tactical situation monitor showing the progress of the Klingons in their war with the Federation.
The uniforms used by the crew of the Enterprise-C were those employed by the original series movies, sans the collared undershirts and the Starfleet insignia belts. This version of the uniform would be reused with Jack Crusher in "Family". The insignia pins now doubled as combadges, and the type 2 phaser from Star Trek: The Motion Picture and Star Trek II: The Wrath of Khan was used as the standard sidearm.
Michael Piller did some work on the screenplay, but left his name out of the credits. This was due to Writers Guild regulations relating to the limits of number of writers being credited to a single script.
In contrast to Captain's log and Stardates, the alternate timeline Picard records a Military log using "combat dates." However, an Okudagram on Picard's desk, seen shortly before Yar enters to ask for a transfer to the Enterprise-C, shows "Captain's log: Captain J-L Picard."
"Yesterday's Enterprise" marks the return of Denise Crosby as Tasha Yar to TNG after Yar's death in "Skin of Evil" (Crosby's last episode filmed was "Symbiosis", which aired before "Skin of Evil"). The events of the episode allowed her to return as Sela, in the "Redemption" and "Redemption II" episodes (as well as later in "Unification II").
The episode wound up needing to be filmed ahead of schedule in order to accommodate the availability of both Denise Crosby and Whoopi Goldberg. Writers initially expressed concern that putting a rush on finishing the script would result in poor or ineffective qualities in the story.
When this episode was first shown, there was a brief exchange between Worf and Guinan where, after he asked, "What is this", she explained that it was an Earth drink called prune juice that was good for you, cleansed the system and made you feel stronger. To this Worf replied, "A warrior's drink!" Subsequent showings of this scene have deleted this exchange.
Although some references state that this is incorrectly regarded as a mistake, Wesley is not old enough to be a member of the alternative Enterprise crew. This is based on Tasha stating that she has been on the Enterprise for 4 years and she joined straight out of the academy. As Wesley is clearly more than 4 years younger than Tasha, he could not yet have completed his Starfleet training.
This is the last episode of the series to feature all nine of its original regular cast members. Denise Crosby and Wil Wheaton would both appear in subsequent Star Trek episodes and films, but never the same ones.
In an early development for the story, Ambassador Sarek (Spock's father played by Mark Lenard) used the Guardian of Forever (Star Trek: The City on the Edge of Forever (1967)) to replace Surak, the father of the Vulcan philosophy of logic who had been killed resulting in a new time-line rather than Tasha Yar performing a similar service.
Ron Moore noted, "We brought Denise back to kill off Tasha Yar a second time. It was a great opportunity to send the character off in a big heroic sacrifice because nobody was really happy with the way she left the series in the first season. Nobody on the show really liked it, the fans didn't like it, I'm not sure even she really liked it. So 'Yesterday's Enterprise' was a chance to kill her right."
In the original script, each alternate Enterprise regular crew members were to be individually seen killed during the final battle with the Klingons. Notably, Data was to be electrocuted, and Wesley was to be decapitated. However time and budget constraints, as well as concerns about the graphic nature, resulted in a reduction of the scene, with only Riker's death depicted on screen.