Brown bears are sexually dimorphic (have two distinct gender forms): males may be 20 to 100 percent larger than females. Although usually dark brown, their coloration varies from cream to almost black. They are very strong and have an excellent sense of smell. They have a prominent shoulder hump, a snout that rises abruptly on the forehead, shaggy fur, long front claws, and a face with a slightly dished profile.

It is a common misconception that bears have poor eyesight. While vision is by no means their most developed sense, studies show that most bear species can see about as well as humans. They also have fairly good hearing. However, their strongest sense is smell: bears are thought to have the best smelling capabilities of all the animals on Earth.