In the U.S., the public has expressed concern over the use of sow gestation stalls via ballot measures in a number of states. Likewise, large companies such as Smithfield Foods and Canada’s Maple Leaf Foods are voluntarily restricting the use of gestation stalls by 2017.  Gestation stalls have already been banned in the U.K. since 1999, with the rest of Europe phasing them out by 2013, and Australia by 2017. On the surface, it may appear that this is a step towards improving the welfare of gestating sows, however, animal welfare is a multi-faceted concept and scientific data is needed to assess all components.  This article describes some of the literature that assesses the different housing systems for gestating sows.