This article presents an overview of the legal liability issues in torts and patent law that arise from the use of transgenic crops produced by agricultural biotechnology. Torts-A tort is a civil legal action whereby the claimant alleges injury or wrong, arising independent of contract, to the person or property of the claimant. The article begins with legal liability claims for damage to property, damage to persons, and damage to economic interests (markets) that may arise with the use of transgenic crops. The tort theories discussed include the legal claims of trespass, strict liability, negligence, private nuisance, and public nuisance. With respect to each tort theory, the discussion points out unique legal issues that are likely to exist specifically because the litigation involves agricultural biotechnology. Patent Infringement-The article ends by focusing on four patent infringement cases that courts in Canada and the USA have decided regarding farmers who used patented seed from agricultural biotechnology without permission of the patent holder. As of May 2003, these are the only four patent infringement cases that have resulted in formal legal opinions by courts construing patent and antitrust laws in the context of farmers saving seeds protected by patents.