A couple of times, a character says, "What the..." He doesn't say the actual word, just "What the.."
I don't know... that may be a reason for the PG rating too?
There is some mild violence, but it really is tame. W/o giving away any spoilers, the ice castle scene w/ Elsa, Hans, & the 2 guards is a little intense & there are some other dramatic scenes as well.
My 4 year old wasn't scared in "Frozen" (although he did get in my lap the 1st time we saw it during the Snow Monster scene); however, the dragon dean in "Monsters U" did scare him.