Cattle are the natural hosts of bovine viral diarrhea virus (BVDV), which causes mucosal disease, respiratory and gastrointestinal tract infections, and reproductive problems in cattle. However, BVDV can also infect goats, sheep, deer, and pigs. The prevalence of BVDV infection in pig herds has substantially increased in the last several years, causing increased economic losses to the global pig breeding industry. This article is a summary of BVDV infections in pigs, including a historical overview, clinical signs, pathology, source of infection, genetic characteristics, impacts of porcine BVDV infection for diagnosis of classical swine fever virus (CSFV), differentiation of infection with CSFV and BVDV, and future prospects of porcine BVDV infection.