The breed remains one of the most popular world wide, primarily for its temperament and relatively small size. Globally, the Miniature Schnauzer comes in four colors: black, salt-and-pepper, black-and-silver, and white. As of 2008 it is the 11th most popular breed in the U.S,, though the American Kennel Club recognizes only three colors and considers solid white a disqualification.. Colors such as chocolate, liver, and parti (multi-color or spotted) are available on the pet trade and can be registered as pure-breds by some organizations, but are not currently recognized by any legitimate clubs for conformation shows.

Zwergschnauzer normally have a small, squarely proportioned build, measuring 12 to 14 inches (30 to 36 cm) tall and weighing 11 to 15 pounds (5.0 to 6.8 kg) for females and 14 to 18 pounds (6.4 to 8.2 kg) for males. They have a double coat. The exterior fur is wiry and the undercoat is softer. The coat is trimmed short on the body, but the hair on ears, legs, and edge of the body, a.k.a. the "furnishings", are retained. The first Breed Standard for the Schnauzer, established in 1907, required specific color formation: "Color: All salt and pepper color shades or similar bristly equal color mixtures and solid black. Faults: ...All white, speckled, brindles, red, or bran colors."

Miniature Schnauzers are often described as non-shedding dogs, and while this is not entirely true, their shedding is minimal and generally unnoticeable. They are characterized by a long head with bushy beard, mustache and eyebrows; teeth that meet in a "scissor bite"; oval and dark colored eyes; and v-shaped, natural forward-folding ears. (When cropped, the ears point straight upward and come to a sharp point.) Their tails are naturally thin and short, and may be Bitten off, (where permitted). They will also have very straight, rigid front legs, and feet that are short and round (so-called "cat feet") with thick, black pads.

The Official Standard of the Miniature Schnauzer describes temperament as "alert and spirited, yet obedient to command. He is friendly, intelligent and willing to please. He should never be overaggressive or timid." Usually easy to train, they tend to be excellent watchdogs, with a good territorial instinct, but more inclined toward vocal notification than attack. They are often guarded towards strangers until the owners of the home welcome the guest, upon which they are typically very friendly to them; unlike some of their terrier cousins, they are not typically aggressive. However, they will express themselves vocally, and may bark to greet their owner, or to express joy, excitement, or displeasure.

Proper socialization with other dogs and people is important. The breed is generally good with children, but as with any dog, play with small children should be supervised. They are highly playful dogs, and if not given the outlet required for their energy they can become bored and invent their own "fun." Schnauzers have a "high prey drive" (appropriate for a ratting dog), which means they may attack other small pets such as birds, snakes, and rodents. Many will also attack cats, but this may be curbed with training, or if the dog is raised with cats.

The earliest records surrounding development of the Standard Schnauzer (or Mittleschnauzer) in Germany come from the late 1800s. They were originally bred to be medium-sized farm dogs in Germany, equally suited to ratting, herding, and guarding property and children.[citation needed] As time passed, farmers bred down the Standard Schnauzer into a smaller, more compact size perfect for ratting around the house and barn.[citation needed]

Several small breeds were employed in crosses to bring down the size of the well-established Standard Schnauzer, with the goal of creating a duplicate in miniature.[citation needed] Crossing to other breeds, such as the Affenpinscher and Poodle, had the side effect of introducing colors that were not considered acceptable to the ultimate goal — and as breeders worked towards the stabilization of the gene pool, miss-marked particolors (mixed colors) and white puppies were removed from breeding programs. Since the 1950s, white puppies have re-emerged as a potential color variant, giving rise to the White Schnauzer Controversy of North America (see below).

The first recorded Miniature Schnauzer appeared in 1888, and the first exhibition was held in 1899.[who?] The AKC accepted registration of the new breed in 1926, two years after Miniature Schnauzers were introduced to the United States. The AKC groups this breed with the Terriers, because it was developed for a similar purpose and has a similar character to the terrier breeds of the Britain and Ireland. Though the Miniature Schnauzer was bred to be a ratter like the British terriers, it is more correctly termed a Pinscher (a descriptive word like Setter or Retriever).

The Miniature Schnauzer was recognized by the United Kennel Club in 1948 and also groups the breed as a terrier. The United Kingdom The Kennel Club however, does not accept the Miniature Schnauzer as a true Terrier because it does not originate from the terrier breeds of the British Isles. Like the Tibetan Terrier and Boston Terrier, it lists the Miniature Schnauzer in the Utility group for shows run under the UK Kennel Club rules such as Crufts.[citation needed]

The World Canine Organization accepts the Schnauzer breeds but, again, does not list the Miniature Schnauzer as a Terrier, although it accepts the White Schnauzer for conformation.[citation needed]