A bioartificial liver that comprises cultured hepatocytes within an artificial device is regarded as a new hope for the treatment of patients suffering from severe liver failure, since highly complicated metabolic functions of the liver cannot be totally replaced by any of the existing blood purification technologies. Nevertheless, the development of a bioartificial liver is a complex problem requiring a wide variety of approaches from the viewpoints of basic and applied sciences, in particular a newly developing field of tissue engineering. The purpose of this paper is to provide an overview of the present status of the bioartificial liver technologies with emphasis on tissue engineering aspects of the design and improvement of the module. Following a brief description of the needs and requirements of the bioartificial liver, several types of extracorporeal bioartificial liver modules based on a wide variety of hepatocyte culture methods are summarized, and future tasks to be accomplished are discussed. A compartmental mass transfer model to quantitatively analyze the performance of the bioartificial liver is also briefly introduced.