When Toto is young, the films that Alfredo gave him catch fire. They burn and ruin the only picture that his mother had of his father. When Toto is a grown up, this "burnt" picture is hanged on the wall totally unharmed.
Toto as a child is shown to be left-handed during the school examination sequence, but as a young man he is right-handed as he marks off the days on the calendar. In addition, when in the army, he fires the rifle right-handed.
When Toto and Alfredo is taking the test at school, there are supervisors walking in the background. They repeatedly "jump" around between shots.
The heights of Toto and his mother change dramatically during the course of their adult lives. Jacques Perrin is much taller than Marco Leonardi and Pupella Maggio is much shorter than Antonella Attili. As a child and teenager, Toto is clearly below average height. In middle age, he is the tallest man at Alfredo's funeral by a clear head.
When Toto is a kid, and he and Alfredo are writing the exam, Toto throws a ball of paper to Alfredo. In one frame, he is throwing it with his left hand and in another frame he is throwing with his right hand.
The 1954 calendar is wrong. All the days are out by one. The calendar shows that 1st April, 1954 is a Friday. In fact it was a Thursday.
When the subtitles are shown for the film "Seven Brides for Seven Brothers" it reads "Unforgivable songs" rather than "Unforgettable songs"
The projection room of the Cinema Paradiso seems to have only a single projector. In those times most theaters had at least two projectors and the film was mounted on multiple reels. It was the projectionists job to switch projectors seamlessly. However, this is not a goof. In rural Italy in the 50s (and later) many small cinemas only had one projector. It could be loaded up with up to 6000 ft of film (the reel that Alfredo is seen showing to the priest is 6000 ft), and 6000 ft of 35mm sound film lasts about 1 hour. During a feature film there would be a short intermission after an hour, when the projectionist could change the reels.
While Toto is in the Italian army, he is shown with a close-cropped military haircut. After he is discharged and returns home, his hair is suddenly long again. That's because he spent a year in the military; more than enough time for his hair to grow back.
When grown up Toto looks at the photos on the wall in his former room you see that Alfredo and young Toto are cut out and glued to the picture of the Paradiso.
In one scene, scenes from the film ...And God Created Woman (1956) are shown. Several scenes later, Salvatore is shown marking a calendar dated 1954. "And God Created Woman" was released in 1956.
When Toto leaves Giancaldo on the train a man with eighties costume, purple shirt and two baggage, is clearly visible.
When the film is borrowed from a neighboring theater, we see that the projector is apparently located in the balcony of the theater, not in an enclosed projection room. Furthermore, the projector has a "magnetic penthouse" sound pickup, an attachment used to play early stereophonic prints. This process would not be invented until 1953 and not used widely until years after nitrate film was phased out.
After several boys are seen admiring an image of the curvaceous Rita Hayworth in what appears to be a new publicity photo for Gilda (1946), the song "Bewitched, Bothered, And Bewildered" is heard, sung by Jo Ann Greer dubbing for Hayworth, but this recording is from Pal Joey (1957) which wouldn't come out for another decade.
As a boy and teen, Toto's eyes are dark brown. But, as an adult, during lightning strikes, his eyes are bluish gray.