The film is about a little boy, as I recall, who has a teddy dinosaur, he takes the dinosaur everywhere and when no one is around the dinosaur comes to life. I remember one scene where he takes the dinosaur to school in his backpack and puts it in his locker, can anyone remember this film? :)
The dinosaur as I remember was green with yellow spots.

OH MY LIFE! Someone else who remembers this film. I used to watch this film OVER AND OVER again when I was young but like you, I have no idea what it was called. Think it must have been a british film. I remember the boy being scared of fish. Did they live near the coast if I recall? WE MUST FOUND OUT WHAT THIS WAS CALLED...

Was it the episode of the Jim Henson Hour called "Living with Dinosaurs"?

Episode 111: Living with Dinosaurs - Muppet Wiki
Living with Dinosaurs (1989) (TV)