Pyrenean Mastiffs are large dogs, typically weighing between 110 to 200 pounds (50 to 90 kg). Males are generally larger than females, standing around 28 to 32 inches (71 to 81 cm) at the shoulder.

Pyrenean Mastiffs are known for their calm and gentle demeanor. They are loyal, protective, and affectionate with their families. While they can be wary of strangers, they are typically not aggressive unless provoked. Training and socialization are important from an early age to ensure well-rounded behavior.

This breed has a thick, double coat that is weather-resistant. The outer coat is long and coarse, while the undercoat is soft and dense. Common colors include white with various shades and patterns, often accompanied by markings in shades like brindle, fawn, or gray.

Pyrenean Mastiffs are known for their calm and gentle demeanor. They are loyal, protective, and affectionate with their families. While they can be wary of strangers, they are typically not aggressive unless provoked. Training and socialization are important from an early age to ensure well-rounded behavior.

These dogs thrive in spacious environments, ideally with a yard where they can roam and play. They are best suited for families or individuals who can provide ample exercise and companionship. They do not adapt well to being left alone for long periods.