When Zenobia's son is killed and she goes down the steps to see him at the end of the film, you clearly see she is wearing two shoes and no longer has the bird's claw on her right foot.
The Troglodyte disappears after its battle with the Tiger. It cannot be seen even on the wide shot when the temple is collapsing.
During the time that Zenobia transformed herself into the seagull, the locket is visible with the magic elixir around the seagull's neck, but when the seagull is in flight, the locket is nowhere to be found.
On Zenobia's boat, during the animated shots the minotaur rows clockwise - mimicking the motion of the oars - but in the live shots he rows counter-clockwise.
The eye patch worn by Zabid changes sides between the right eye and the left during the sequence when he intercepts Zenobia's boat, indicating reversed shots.
When the bee is becoming enlarged, it can be heard buzzing for quite a while before it starts to move its wings.
When Sinbad (Wayne) fights the giant saber-tooth tiger in the ending sequence, the tiger has no shadow while Sinbad has several shadows.
When Farah and the Baboon are playing chess, the Baboon is playing the red pieces and Farah the white. There are however a few captured red pieces on the Baboon's side of the board when they should be on Farah's side of the board.
The foreground characters and backgrounds (of Petra) are in focus, yet the characters in-between are out of focus in almost every single blue-screen shot set outside Melantheus's castle. This is optically impossible.
As the sabre-tooth tiger is pacing around, its claws are always exposed. Being a member of the cat family the claws would be retractable and only be visible when attacking.
Dione's dress is clearly a modern dress with a zipper in the back.
Although it is not specified in which time period the film is set, the mentions of Allah makes it clear the events take place not before the 7th century AD. However, Melanthius claims he was friends with Archimedes of Syracuse, who (historically) died in 3rd century BC. Although Melanthius is a famous alchemist and inventor, there is no indication that he's made any kind of 'eternal youth' potion, to keep himself alive for centuries.
When Sinbad sets out to reveal the baboon to Melanthius, Melanthius opts instead to demonstrate his telepathic powers by identifying the concealed creature without looking upon it. As he does so, he describes it as "an arboreal anthropoid of the genus, Papio", a taxonomic classification that would not be established until 1777.
When Sinbad and his crew exchange their first lines of the picture, Maroof can be seen speaking to Sinbad with an annoyed facial expression, but no audio comes out.