But some of you thought the rating was right.
Ria, 13, from Staines said: "I think it deserves a 12 as most young children who Spider-Man comics appeal to would be scared by some of the scenes."
A few local councils have used their powers to make the film a PG-12, which means children under 12 can go with an adult.
Lots of you, including Ernie, 11, from Enfield, agreed with this. "I do agree with it being rated a 12 because it would seem too violent for kids, but they should have made it a PG-12, because then if an eight year old saw it with a parent it's their fault."
And in our vote, nearly 40 per cent of you think Spider-Man should be a PG, but 34 per cent thought PG-12 was better.
But the final word goes to 10-year-old Lisa from Coventry, who had this to say: "I wish all cinemas would see sense and drop the 12-rating."