Lactation failure in swine is a rather common disease entity that has perplexed swine producers and veterinarians for generations. While the disease has been studied extensively for years proper prevention and treatment methods have been elusive. The most common name for the disease is the mastitismetritis- agalactia (MMA) complex. As will be discussed in this review, metritis is rarely a part of the disease. It has been suggested that a more descriptive name for the disease complex is the periparturient hypogalactia syndrome.