This species is recognizable for its dark coloration, with some populations being almost entirely black. Others may be dark brown or gray, with darker blotches that turn into bands running down their back. Juveniles are much lighter than adults, and darken as they age.

They are found primarily in mesic woodlands, mesquite scrublands and other habitats with abundant wood debris & leaf litter; but sometimes they may be found in grassland habitats. It preys on small mammals, lizards, and birds. Females give live birth to 4 to 21 juveniles, and this was the first rattlesnake species to be observed to exhibit maternal care with its offspring.

The Arizona black rattlesnake was previously considered a species of the prairie rattlesnake (Crotalus viridis), but has since been elevated to full species status.

Arizona black rattlesnakes are actually social animals. Individuals have been shown to form purposeful (non-random) associates with other rattlesnakes of the same species; some individuals prefer larger communities, some smaller, and others live most their lives solo. These groups include both relatives and unrelated snakes.