Watch it online from the Internet Archive:
1000 Misspent Hours says,
There is almost nothing you could ask for in a late-50’s mad scientist movie that The Brain that Wouldn’t Die doesn’t deliver, and as if that weren’t enough, it throws in a bunch of other stuff that you’d never think to ask for in the first place.and concludes by saying
Small wonder that it has become one of the world’s few legitimate cult classics.
Moria has a short review. BadMovies.org has plot information and still shots from the film.
4/29/2009: Radiation Cinema has a review.
9/6/2009: SFSignal is featuring it (from youtube) as their Sunday Cinema post.