The Spanish Mustang is a medium size horse ranging from 13.2 to 15 hands with an average size of approximately 14.2 hands with proportional weight. They are smooth muscled with short backs, rounded rumps and low set tails. Coupling is smooth and the overall appearance is of a well-balanced, smoothly built horse. The girth is deep, with well-laid back shoulder and fairly pronounced withers. They posses the classic Spanish type head with a straight or concave forehead and a convex nose which is in contrast to the straight forehead and nose of most breeds.
Ears are medium to short and usually notched or curved towards each other.
Necks are fairly well crested in mares and geldings and heavily crested in mature stallions. Chestnuts are small or missing altogether, particularly on the rear legs. Canons are short, upper foreleg is long, with the canon bone having a larger circumference than other breeds of comparable size and weight. Long-strided, many are gaited, with a comfortable four bear gait such as the amble, running walk or single foot. They are hardy animals and tend to be less prone to injury, particularly of the legs and feet, than other breeds.