Porcine respiratory coronavirus (PRCV) is antigenically related to transmissible gastroenteritis virus (TGEV). Differential serological diagnosis between PRCV and TGEV infection is not possible with the classical sero-neutralization test. Infection with PRCV or TGEV induces antibodies which neutralize both viruses to the same titer. However, the enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) can differentiate between PRCV and TGEV infection. This study was carried out to investigate the prevalence of PRCV infection of swine in Gyeongnam province. A total of 391 serum samples from 37 herds in Gyeongnam were examined for antibody to PRCV using blocking ELISA. All serum samples were collected from 130- to 150-day-old pigs between August and December 2006. By ELISA, 182 out of 391 sera tested (46.5%) and 29 out of 37 sample herds (78.4%) were positive against PRCV. Our data suggested that seropositive herds for PRCV are distributed diffusely throughout Gyeongnam. The PCR methods were established to diagnose PRCV spike protein (S) gene. PCR were conducted to identify the PRCV genome against 150 pigs in PRCV antibody positive herds.