In Portugal, where Estrela Mountain Dogs are still used for herding and protecting livestock and as both marine and police dogs, they are known as Cao da Serra da Estrela. In the past they were also used to pull milk carts. Because of their intelligence and consistent work ethic, they are among the working dog group and are considered natural guard dogs.

Estrelas can live well in all climates and terrains because they have thick coats and are accustomed to working in the mountains as well as cold, snowy weather.

The Rare Breed Network has highlighted the positive abilities of Estrela Mountain Dogs and has been endorsed by both the Estrela Mountain Dog Association of the United Kingdom and the Estrela Mountain Dog Association of America.

Estrelas love children and will often ignore adults if they are present. At the same time, these dogs often choose one family member, likely the one who cares for and trains them, as the master to whom they will be totally faithful.
The Estrela personality ranges from fierce if he senses danger, to extremely gentle and loving. While the fierceness was needed to ward off predators while guarding sheep and goats, they were also known to clean newborn kids and lambs while their mothers recovered.

Estrelas live to be about 14 years old and an average litter will produce between 2 and 12 dogs.

There is now what is called an "Estrela Ring" on the Internet that includes breed specific web sites, boards, and chat rooms for Estrela dog lovers to talk about their beloved pets.

The Estrela Mountain Dog is one of 75 breeds on a list of potential canines restricted or banned in the United States. The dogs on this list have either been named in legislation that has been tabled, proposed, or passed. Some are included under restrictions or bans on Pit Bulls and Wolf hybrids. However, it is uncertain just where and why the Estrela is included on the list. The Responsible Dog Owners of the Western States has opposed all legislation on dogs. They believe owners should be responsible for keeping their pets under control at all times.

Estrela Mountain Dogs are aggressive animals by nature but can be easily trained to understand proper behavior, particularly jumping up and nipping people. Between 1986 and 1996, dog bits that required treatment by doctors rose 37 per cent over previous years. During the same time period, the total number of dogs in America dropped 2 per cent. Most attacks, approximately 61 per cent, occurred in the home and 90 per cent of victims were children.

Ami Moore, a writer with the Chicago Dog Whisperer says, "Dogs are born knowing only one law: the Law of the Jungle. It is hard-wired into their genetic code. Either the human sets the rules, boundaries, and limitations or the dog sets them. Understand that when dogs rule people by the Law of the Jungle, people get hurt."