Put me down in agreement with the reviewers here who enjoyed this film. No, it's certainly not remotely great and I have seen much better vampire flicks, but the terrific Zucco, decent writing, and competent acting from the rest of the cast make it slightly better than average.
In regard to Zucco, I have seen him in many films and he never fails to do a good job, regardless of what he has to work with. In this movie, he's the glue that holds this plot together from beginning to end. The way he makes the two brothers distinctive is to be lauded. Privately, he might have hated this genre of movie, but you wouldn't have known it from the gusto that he gives his dual role.
It's always good to see Dwight Frye, even though this wasn't his best performance. He played countless crazy or weird characters throughout his career, yet they usually differed due to his unique characterization he gave to each role.
Some here have complained about the sound and other defects in the quality of the film, which isn't fair since the vast majority of us have seen this film only from public domain copies. For example, the copies of "It's a Wonderful Life" that I saw as a kid weren't half the quality of the actual master that we now see around the holidays. Until a worthy copy shows up, I'll refrain making a judgment on that aspect of "Dead Men Walk."
All in all, the movie is entertaining. If you like horror movies from that era, you probably wont be disappointed.