When a little girl is knocked down it is discovered that there are only three donors of the right blood type to help with a life-saving operation. One is a murderer awaiting execution, one an atomic scientist selling secrets, and one an international footballer about to get his hundreth cap. Written by Jeremy Perkins

The fire station seen in the opening credits is actually Station 127 and is located in Carson, California at 2049 223rd Street (off Wilmington, and across from the Arco Refinery). Station 127 was renamed "R.A. Cinader Memorial Fire Station 127" after the death of "Emergency!" producer R. A. Cinader.

Universal Studios renumbered their fire station to 51 in honor of the show.

One of the three squads (the 1972 Dodge Ram D250 rescue vehicles driven by the paramedics) has been fully restored and is now located at the Los Angeles Fire Museum in SouthGate, California.

The fire engine used for most of the series run has an interesting history. It was donated new by the manufacturer, Ward LaFrance, with the condition that the engine be put in active service after the show. Universal turned it over to the LA Country Fire Department (which runs the fire station on Universal's lot). The LA County Fire Department traded the engine to the Yosemite Fire Department for their 1930 vintage engine that went to the LA Country Fire Museum. Yosemite Fire Department still uses the engine to this day. The Yosemite Fire Department had to raise the ceiling of their firehouse by 3 inches to accommodate the new engine.

The dispatch controller who calls in the alarms to the Station 51 intercom was played by Sam Lanier. Lanier was not an actor, but was actually a real-life emergency dispatcher. Jack Webb wanted a real dispatcher's voice to lend authenticity to the role, and show the professionalism of the actual LA dispatchers.

Martin Milner (Officer Pete Malloy) and Kent McCord (Officer Jim Reed), from another Jack Webb series, "Adam-12", occasionally showed up in cameos at Rampart Hospital. After appearing in the "Emergency" series premiere, they later appeared in another first-season "Emergency" episode. However, this second appearance is in an installment of their own TV show "Adam-12", which the Station 51 crew watch on the firehouse TV. After being established as "real" people, no explanation is given for their subsequent appearance in a dramatic TV show.

This show was John Travolta's television debut

Linda Kelsey's TV debut.