Pre-production work on this film included over 1,200 storyboard sketches.
Produced at a then-staggering cost of $13 million, the film went on to become Paramount's biggest-grossing movie to that time. For years it ranked second only to Gone with the Wind as the most successful film in Hollywood history.
Producer/Director Cecil B. DeMille reached 75 years of age during the production of this film, making him the oldest working Hollywood director. He later suffered a heart-attack on the set, returning to the set only two days later. After this was completed, he planned on another epic production. He died in 1959, before he could direct or produce another, making this his final film.
Several shots that appear throughout the movie are shots that were matted together from scenes shots on location in Egypt and scenes shots at the Paramount Studios in Hollywood. Most notable scenes featuring this multi-location matte-shooting are the scenes which Moses and Sethi watch the Obelisk being raised; the slaves in the background were shot in Egypt, the foreground with Moses and Sethi shot in Hollywood, and the background pylons being matte paintings.
Special Effects Property Master William Sapp created the effects that turned the waters of the Nile red. Red dye was pumped into the water through a hose at the point where Aaron touched the river, with his staff. Sapp also created the vessel that was used by Rameses' priest in an attempt to restore the waters. The vessel had two chambers: one that was filled with clear water and which was located near the vessel's opening, while the other chamber was filled with red-dyed water was located near the bottom of the vessel. As the vessel was tipped to empty its contents, the clear water poured out first, and as the vessel was tipped further, this released the red-dyed water into the "river" on the sound stage. There were six of these vessels that were made for the film, but only two were used during production. The reverse shot showing the red water extending out into the sea was created through animation onto shots of the Red Sea that had been photographed in Egypt.
The cloud special effects used during the parting of the Red Sea scenes, would later be repeatedly used in various movies by director Steven Spielberg.
The effect of clouds that appear over the Red Sea was accomplished using a "cloud tank". A glass tank is filled with water and paint is poured into it. By varying the density of the paint, and the salinity of the water, it is possible to get several distinct layers.
The film is usually very slightly edited for TV transmission, although because of numerous and lengthy commercial breaks, most showings clock in at close to four-and-a-half hours. Its length is 3:40, three hours and 40 minutes, commercial-free and continuous on two DVD's. This has led to some humorists commenting as if it had been "trimmed to seven commandments".
The highest-earning live-action film, was filmed in the 1950's and held the record, for forty-eight years, The Passion of the Christ broke the record, in 2004.
The illusion of the Red Sea parting was achieved by large "dump tanks" that were flooded, then the film was shown in reverse. The two frothing walls of water were created by water dumped constantly into "catch basin areas" then the foaming, churning water was visually manipulated and used sideways for the walls of water. A gelatin substance was added to the water in the tanks to give it more of a sea water consistency. Although the dump tanks have long since been removed, the catch basin section of this tank still exists today on the Paramount lot, directly in front of the exterior sky backdrop, in the central portion of the studio. It can still be flooded for water scenes, but when not being used in a production, it is an extension of a parking lot.
The last line of the film "Proclaim liberty throughout all the land, unto all the inhabitants thereof" was taken from Leviticus 25:10 of The Bible. The verse is also printed, on the Liberty Bell.
The orgy sequence took 3 weeks to film.
The Paramount mountain at the beginning of the film was a stylized version of the studio's logo. The mountain retained its conical shape but with a red granite tone and a more angular summit under a red clouded sky to suggest the appearance of Mount Sinai for this single motion picture. Its circle of stars faded in with the announcement: "Paramount Presents - A Cecil B. DeMille Production."
The pillar of fire, which kept the Egyptians from getting closer to the Israelites just before they crossed the Red Sea, was not achieved through the use of actual flames, but was instead, an animated "cartoon fire". Of all the special effects in the film, it is the one that looks the least realistic to modern audiences, and probably seemed just as unrealistic in 1956.
The red smoke on top of Mt. Sinai, which symbolized God's presence on the mountain, was a matted special effect superimposed over a shot of the actual Mt. Sinai filmed on location.
The script contained 308 pages with 70 speaking parts.
The special effects work was so extensive that it was not completed by the final edit. The released version contains fringing during some blue screen shots which the crew did not have time to correct.
There is a longstanding rumor that future Cuban dictator Fidel Castro was an extra in this film, possibly playing an Egyptian soldier. In her book "My Lucky Stars", Shirley MacLaine recalls asking Castro if he indeed was in the film, and she received an ambiguous answer.
This is perhaps the only Paramount film in which the VistaVision "Motion Picture High Fidelity" logo, together with its accompanying musical fanfare, does not appear at all.
This was Cecil B. DeMille's only movie made in widescreen. Four years had elapsed between DeMille's The Greatest Show on Earth and The Ten Commandments, by which time widescreen films had become standard practice. In 1952, when "Greatest Show" was released, all films, except for "This is Cinerama", were still being made in the old non-widescreen Academy ratio.