Failure analysis is a valuable tool in determining product liability. The legal and technical definitions of product failure are reviewed. Root causes of product failures can be categorized as (1) physical, (2) human and/or (3) latent (systemic) or by the stage in the product life cycle (material, design, manufacture and/or service). Failure analysis is used to identify the physical cause(s) of failure (distortion, fracture, wear and/or corrosion). The process of failure analysis is outlined. Case histories of failure analysis are illustrated with numerous photographs, fractographs and photomicrographs.