The vehicle used for the Ecto-1 was a 1959 Cadillac professional chassis, built by the Miller-Meteor company. The ambulance/hearse combination was the end loader variety. Dr. Ray Stantz found the vehicle shortly after he mortgaged his mother's house to buy the Firehouse. Because of his mechanical skills, he was able to repair the vehicle, which he acquired for $4,800.

After repairs were completed, the vehicle had quite a unique character. It became a well-recognized symbol for the Ghostbusters franchise. The vehicle had enough room in it to store Proton Packs for all of the crew, along with Ecto Goggles', P.K.E. Meters, and a slew of Traps.

After the Ghostbusters were shut down, the Ecto-1 was used primarily for transport to and from appearances at such places as children's birthday parties. It fell into a state of disrepair, and is seen spewing smoke, and having various other mechanical problems.

Following the Ghostbusters' return to business after capturing the Scoleri Brothers, the Ecto-1 got an overhaul and was renamed Ecto-1a.

A further updated version of the Ecto-1 appears in during the Thanksgiving 1991 weekend, Ecto-1b. This version is similar to the Ecto-1a, but adds a Super Slammer Muon Trap on the roof which enables it to capture smaller ghosts much more quickly than the portable versions, as well as adding the possibility of capturing much larger ghosts.