The longevity or productive life of sows is one of the important components that contribute to the economic bottom line of swine production. Involuntary sow culling rates caused by locomotion failure, reproductive failure or death have been growing in recent years causing many females to be culled before they reach their most productive parities and before the investment costs of those females have been recovered. In addition to factors such as management, sow condition, health, nutrition, and facilities, there are likely to be genetic components controlling sow longevity that have yet to be fully identified. Research ongoing at Iowa State University, in conjunction with Sygen and PIC, has focused on identifying the genes associated with variation in sow longevity.