Bernese are outdoor dogs at heart, though well-behaved in the house; they need activity and exercise, but do not have a great deal of endurance. They can move with amazing bursts of speed for their size when motivated. If they are sound (no problems with their hips, elbows, or other joints) they enjoy hiking and generally stick close to their people. Also, most Berners are herding dogs, which means when around other dogs, it tries to form a pack. Many also won't want to fetch a ball or a stick naturally like Labs or Goldens. It's just in their nature.

The Bernese temperament is a strong point of the breed. They are affectionate, loyal, faithful, stable, intelligent, but sometimes shy. The majority of Bernese are friendly to people, and other dogs. They often get along well with other pets such as cats, horses, etc. They are trainable provided the owner is patient and consistent in training; Bernese need time to think things through. They do not respond well to harsh treatment, although Bernese are willing and eager to please their master. Bernese love to be encouraged with praise and treats. The breed is sweet and good with children, despite their great size. Overall, they are stable in temperament, patient, and loving.

Bernese Mountain Dogs are slow to mature, and may display noticeable puppy-like tendencies until 2½ years of age. For example, a consistent playful behaviour feature is to run through the owners legs and lean elatedly into the humans legs, even when calm.