The preparation of recombinant pharmaceutical proteins is one of the major challenges of biotechnology. Mammalian cells are required for a number of proteins which must be modified posttranscriptionally. Animal cell lines cultured in fermentors are presently the major source of complex proteins. The milk of transgenic animals proved to be a possible source of pharmaceutical proteins and one of them, human antithrombin III, has been approved by the EU (EMEA) and US (FDA) medicament agencies. Several species are being implemented for this purpose. Rabbits are one of these species. It offers several advantages: low cost to produce transgenic founders, rapid reproduction, easy and cheap scaling up, easy breeding in pathogen-free conditions and insensitivity to prion diseases. Rabbits are thus an efficient tool to prepare several kilograms of a recombinant protein per year.