The Neapolitan Mastiff is a member of the working group and it is used today as a watchdog, family pet and a show dog. It is a massive dog, being a descendant of the mammoth war dogs of the Middle East, the Molossus. This dog was originally bred to fight against bears, gladiators, and lions as a form of entertainment. It was also used as a war dog. Neapolitan Mastiffs fought alongside the Roman legions during the conquest of Europe, and they spread their breed throughout the land.

The Neapolitan Mastiff is large boned, massive dog that weighs up to 16 stones. It has a large head with an intelligent expression and lots of loose skin on its body, hanging into wrinkles and folds on the head. Its gait is bear-like and slow but it can trot when it needs to cover ground. The Neapolitan Mastiff seldom gallops. Its rare forms are found in brown white and tan stripe where its coat may be grey, tawny, black or mahogany. The Neapolitan Mastiff may have white patches on the chest or feet. Its ears are half pricked and cropped.

By temperament, the Neapolitan Mastiff is fearless and protective. It loves being around family and friends. It is cautious around strangers but it will relax once it gets to know the person. The Neapolitan Mastiff seldom barks unnecessarily; it only barks if provoked. Being a stubborn dog, it does not require much training, but once it understands what you want, it will obey you.

The Neapolitan Mastiff has a dominant attitude. It is important that you make it realize from puppyhood that you are the boss. Males are naturally more aggressive and dominant than females, but females work better with children as they are more docile. The Neapolitan Mastiff generally gets along well with children. Males cannot get along with other male counterparts because of their dominant nature. However, they can get along well with non-canine pets if raised together. The male Neapolitan Mastiff tends to drool heavily, especially in hot weather or after drinking water.

The large body and excess wrinkles of the Neapolitan Mastiff demands extra care and maintenance. You have to give it regular baths and keep its face and body clean all the time. It is important to take care of its wrinkles well, lest its skin starts to smell and develop acne, which will lead to infection. So make sure that the Neapolitan Mastiff's face and wrinkles are kept as dry as possible to prevent any infection.

The Neapolitan Mastiff is prone to hip and elbow dysplacia, arthritis and OCD. They are also prone to near-sightedness and are sensitive to anesthetics and tranquilizers. Because they cannot tolerate heat well, Neapolitan Mastiffs have to be kept in the shade, and given lots of water on hot days.