Brachypelma smithi, more commonly known as the "Mexican Redknee Tarantula," is very commonly kept as a pet. In the 1970s, many of these spiders were exported and it is now illegal to capture them in the wild for exportation. However, it is perfectly fine to breed them in captivity and sell the spiderlings.

A fairly peaceful tarantula, the Mexican Redknee very rarely bites. However, it may bite if provoked. Because it is generally non-aggressive it may be a good tarantula for beginners, though its higher cost may be prohibitive to some. While its venom is usually nontoxic, some people may suffer a severe allergic reaction. The Mexican Redknee is more likely to kick hairs than bite. It is a terrestrial species, meaning it spends most of its time on the ground. However, they do burrow under rocks in the wild. They molt from time to time, which can take up to three months. As is true with other tarantula species, females have a significantly longer lifespan than males. The average male will live to at most 10 years of age, while females may live as long as 25 years or more.

The Mexican Redknee Tarantula is fairly large, averaging between five and seven inches in leg span. They have a dark brown or black body with orange and red knees (hence the name).

The Mexican Redknee Tarantula is, as the name suggests, native to the coastal and desert areas of central Mexico.

The Mexican Redknee Tarantula is a desert species and should be kept at very low humidity and moderate to high temperatures (65-90 degrees Fahrenheit). Water should always be available. Additional humidity may be added when molting, but not too much. They should be kept in a large tank with several inches of substrate. They should be fed crickets or other similar sized insects. If a Mexican Redknee stops feeding, it most likely means it is ready to molt. It does so on its back, so if it is on its back it is not necessarily dead.

Mating the Mexican Redknee can be rather difficult, as the female's opinions on the matter can differ from docile acceptance to bloodthirsty cannibalism. The pair should be separated at the first sign of female aggression. After mating, egg sac will likely appear between two and eight months later and the spiderlings will emerge after about 90 days. However, it is quite likely for females to eat their egg sacs.