The Corgi is proportional to larger breeds but has shorter legs, yet has a sturdy appearance and an athletic body that helps it herd livestock such as poultry, sheep and cattle. They are short so if livestock tries to kick the dog, the hoof goes right over the dog's head. Its body is long, and it has a naturally long, bobbed, or artificially docked tail and erect ears. The corgi's head should be foxy in shape and appearance.

Pembroke Welsh Corgis are 10 to 12 inches (25 to 30 cm) tall from their feet to the top of their shoulders. The length from the shoulders to the set on of the tail is 40 percent longer than their height. Pembrokes in peak athletic condition weigh Male: 22–26.5 lbs (10–12 kg), Female: 22–24.3 lbs (10–11 kg). They reach their full height by 9 months old, but their bodies keep filling out until they reach full maturity at two years. Pembrokes have a big appetite, so they can weigh up to 40 pounds (18 kg) if allowed to overeat. Pembroke Welsh Corgis (Corgwnin Welsh) can benefit from portion control and exercise.

Pembroke Welsh Corgis are very affectionate, love to be involved in the family, and tend to follow wherever their owners go. They have a great desire to please their owners, thus making them eager to learn and train. (They can be stubborn, however.) The dogs are easy to train and are ranked as the eleventh smartest dogin Stanley Coren's The Intelligence of Dogs. Besides herding, they also function as watchdogs due to their alertness and tendency to only bark as needed. Most Pembrokes will seek the attention of everyone they meet and behave well around children and other pets. It is important to socialize this breed with other animals, adults and children when they are very young to avoid any anti-social behavior or aggression later in life. Due to their herding instinct, they love to chase anything that moves, so it is best to keep them inside fenced areas. The herding instinct will also cause some younger Pembrokes to nip at their owner's ankles to get attention, but this behavior can be stopped through training and maturity.

There are five "allowed" colors for Pembroke Welsh Corgis:
* Red, with or without white markings, which may appear on the feet and legs, muzzle, between the eyes and over the head as a small blaze, and around the neck as a full or partial collar. Red is the most commonly seen color as it is the genetically most dominant of the colors.
* Sable with white markings, which is like a red but with a light peppering of black.
* Fawn with white markings as described above, which is a lighter red (the red can be from a fawn to a deep red)
* Red-headed tricolor, which is a black dog with a red head, red spots above the eyes, on the sides of the muzzle on the legs and in the ears and around the anal area they also have white markings as described above and the white markings can often obscure some of the red markings of the muzzle and legs. A dog would be considered a mismark if they were black and white with no tan present.
* Black-headed tricolor, (the most recessive color genetically) which is a black and red dogs with red markings (in the same places you would see red on a black doberman) and white markings as described under Red above. A dog would be considered a mismark if they were black and white with no tan present.

Pembrokes should have a "fairy saddle" marking on the side of their shoulders caused by changes in the thickness, length and direction of hair growth. The phrase "fairy saddle" arises from the legend that Pembroke Welsh Corgis were harnessed and used as steeds by fairies. The white markings can be on the feet, chest, nose, stripe on the head, and as white partly or fully around the neck. Pembroke Welsh Corgis have an undercoat of fine soft fur and an overcoat of coarse hair, which makes their coat water resistant. Their coat should be medium length with a little extra on the chest plate.

The Pembroke Welsh Corgi has a double coat with medium length hair and are fairly heavy shedders. In addition to their regular shedding, they blow their coat twice a year (in the spring and fall).

Faults in the breed include: "fluffies"who have long hair, and "bluies," which is a dilute colour. In a bluie that is a red dog, the red color would seem to have a bluish cast to it and the eyes will be light (instead of a dark brown) and the nose, eye rims, lips and pad colour would be slate gray instead of black. In a black dog, the areas that would be black in a black dog are instead a slate blue gray. As in the red, the eyes will be light and the nose, eyerims, lips and pads will be slate gray. "Whities" have white in abnormal areas. Fluffies, bluies, and whities should not be bred due to their genetic faults. Other faults include smaller toy-like Corgis, obviously oversized dogs, and Corgis with all short hair as in a Doberman.

Pembroke Welsh Corgis are one of the natural bobtailbreeds with the C189G T box gene. This gene is semi-dominant and lethal in its homozygous form. This gene means that the breed is naturally born with a tail or with a bobtail of varying lengths, but most puppies are docked after birth. There are several theories on why they are docked outside the written breed standards. Docking has been a criminal offence in the United Kingdom since 2006. The Kennel Club,the United Kennel Club, and the FCI allow tails to be shown in conformation, only the AKC Standard states the tails should be docked no longer than 2 inches (5 cm). Breeders band the tails or have a veterinarian dock the tails within five days of their birth.