The actresses have been close since attending the same high school in Sydney, Australia, and they both appeared in 1991 independent drama Flirting.
Now they are hoping to work together once more, with Watts admitting they have spent "a long time" searching for the right movie for them to both star in.
Kidman tells EOnline.com, "We're looking. Somebody think of something, please!" while Watts adds, "We've been looking for a long time now. But both of us have... picky tastes. It has to be the right piece."
The two friends recently wrapped films playing real-life royalty - Watts is portraying British royal Diana, Princess of Wales in Diana, while Kidman plays Grace Kelly in Grace of Monaco.