Caveat emptor is a Latin legal maxim meaning "let the buyer beware". Under contract law under common law, the buyer of goods, personal property or real property has a positive duty to ensure whatever is being purchased is fit for its intended purpose. This includes both a duty of physical inspection and a duty to question the seller. The seller has no corresponding duty to disclose. As such, absent misrepresentation or fraud, the buyer has no remedy if there is either a latent defect or patent defect in whatever is being purchased after the buyer takes possession.

The doctrine has been modified somewhat in the 20th century to protect purchasers who are unlikely to have had a proper chance to fully inspect goods before they are purchased. Lemon laws protect purchasers of vehicles who find the vehicle needs frequent ongoing repair to keep it operating. The doctrine also has limited application to consumer goods with a latent design defect, such as computers, as a buyer is unlikely to have an opportunity to determine if the goods they bought were thought to be faulty in some way by the manufacturer.