The heavy coat of Lhasas can also be explained by the geographical features of Tibet: the temperature frequently drops below freezing thus making it hard for a dog to survive without sufficient insulation. Lhasas were rarely groomed by their owners thus allowing the breed to adapt to the harsh weather, although when they are in warm climates, such as the south-western U.S., many owners prefer to have the coats trimmed.

In 1901 Mrs. A. McLaren Morrison brought the Lhasa Apso to the UK where it was registered as an official breed in The Kennel Club in 1902.

The original American pair was a gift from Thubten Gyatso, 13th Dalai Lama to C. Suydam Cutting, arriving in the United States in the early 1930s. The American Kennel Club officially accepted the breed in 1935 in the Terrier group, and in 1959 transferred the breed to the Non-Sporting group.

Recently, DNA Analysis has identified the Lhasa Apso as one of the 14 most ancient dog breeds.

In the 1950s the Lhasa Apso and Maltese were accidentally bred creating a type of dog that later became known as the Kyi-Leo rare dog breed in the 1970s.