The Scottish Terrier is a short-legged, compact, relatively heavy-boned dog, giving the impression of great power in a small package. This combination is essential in a dog that must meet tough adversaries in tight spaces. Its coat is a combination of dense undercoat and extremely hardy and wiry outer coat, about 2 inches in length. The distinctive eyebrows and beard add to its expression, which is keen and sharp.

Nicknamed the Diehard in reference to its rugged character, the Scottish terrier is a tough, determined character, ready for action. It is fearless and feisty and may be aggressive toward other dogs and animals. It is reserved, but friendly, with strangers, and devoted to its family. Although independent and stubborn, it is sensitive. It tends to dig and bark.