During an interview for the PBS series "Pioneers of Television," Noah Wyle said that while filming some of Carter's Africa storyline in the Kalahari Desert, the real on-set medic passed out from the heat, and Wyle (who by that time had been filmed pretending to perform hundreds of simulated medical procedures for the television show) inserted a real I.V. and hooked the medic up to a real saline drip.
Goran Visnjic named his character after the writers could not develop an appropriately Croatian name. The character is named for Visnjic's nephew (Luka) and his best friend (Kovac).
Anthony Edwards was the first choice to play the part of Dr. Mark Greene. Unfortunately, Edwards was committed to directing a feature film when he couldn't film the pilot. By sheer luck, his feature was pushed back, and he was able to film the pilot instead.
If anything had gone wrong during the live episode broadcast, such as a technical failure or forgotten dialogue, the producers had additional actors ready to improvise a scene that would have been inserted to cover. This contingency was never used.
After [Anthony Edwards]'s real-life wife, [Jeanine Lobell], gave birth to another baby girl, it was his call to leave the show, near the end of the 2001-02 season, to spend a lot more time with his family, in addition to pursuing other projects.