One of the easiest ways to find adoptable Chihuahua puppies is to work with a rescue organization that focuses on the breed. Use pet adoption websites such as Petfinder.com to search for Chihuahuas in local all-breed shelters.
Since Chihuahuas are a popular breed as of 2015 and they are often purchased on impulse from pet stores, they also often end up in need of homes. Locate Chihuahua rescue groups by contacting Chihuahua breed clubs or responsible Chihuahua breeders or by using the contacts provided by the American Kennel Club Rescue Network.
Chihuahuas are often produced in puppy mills, and sometimes those unethical breeders pretend to be rescue groups to sell their excess or undesirable puppies. Be sure to check out any rescue organization thoroughly before adopting a Chihuahua. A valid rescue group should be a non-profit organization and ask many questions about you to make sure you are a good fit for a Chihuahua puppy.
Local all-breed shelters are another good avenue. In addition to adoption websites, most shelters list adoptable dogs on their own websites. Since purebred puppies may be adopted quickly, it is also a good idea to visit the shelter in person at times. Some shelter staff may be willing to take down your contact information and let you know if an adoptable Chihuahua arrives.