Commonly called a Yorkie, Yorkshire terriers, which originated in England, are a small breed of dog listed in the toy category. They have beautiful silky, long, blue coats and playful, fun terrier behavior. The average size for both male and females is from eight to nine inches and weigh up to seven pounds. The American Kennel Club places each dog breed into a group and Yorkshire terriers are in the toy group because of their small size. The AKC standard for Yorkshire terriers is seven pounds and under, and most in the show ring range from five to seven pounds. Within the Yorkshire terrier breed there are no sub-categories.

A teacup Yorkshire terrier is not a separate dog breed standard or classification as there is no such breed of dog as a teacup Yorkie. Teacup or tiny is a size category made up by breeders for individuals looking for a tiny lap dog in the two or four pound range. They use this term to help possible pet owners find the size or type of Yorkie they want easier, as there is a large number of people looking for a tiny or "teacup" Yorkie. Although there are a few Yorkie teacup and show breeders that breed strictly for money, most breed for temperament, health, and quality.

The difference between most show breeders of five to seven pound Yorkies and breeders of teacup Yorkies from two to four pounds is the size of the puppies. In a show litter, sometimes a puppy remains small because of genetics or it is premature. Most breeders specializing in teacup Yorkies study the pedigree and genetics of their stock and breed for temperament, size, health and quality the same as show Yorkie breeders.

Although teacup Yorkies are very tiny, most are oblivious to this. They are energetic, scared of very little, playful, intelligent, brave, loving, loyal, sweet, adventurous, and fun. They are highly affectionate with their owners but are sometimes aggressive towards other small animals and can be territorial and suspicious of strangers. Early socialization of teacup Yorkies helps prevent this when they reach adulthood. Teacup Yorkies are a wonderful lap dog, dislike being ignored, love human attention and enjoy their owners continuously holding and making a fuss of them. They are dependant and demanding so require a lot of attention.

Because of teacup Yorkies' small size, they are ideal for smaller dwellings such as apartments or homes without a large yard. They do benefit from regular playing and running but are very active so do not require a lot of exercise. They require regular grooming including daily brushing. Teacup Yorkies need their ears, eyes, and teeth cleaned regularly. Their fragile, tiny stature makes the teacup Yorkie a better pet for older, considerate children and not recommended for a home with small children. With a lot of love and proper care, a teacup Yorkie will provide you with many years of enjoyment.