Porcine circovirus type 2 (PCV2) is associated with many diseases especially postweaning multisystemic wasting syndrome (PMWS), which has brought huge economic loss to the swine industry worldwide. Viral detection will pave the way for this disease prevention. Herein, we developed a facile, rapid and ultrasensitive method for detection of PCV2 based on gold(III) enhanced chemiluminescence immunoassay (CLIA). The gold(III), dissolved from the gold nanoparticle-monoclonal antibody conjugate, served as an analyte for the indirect measurement of PCV2. Under the optimal conditions, the detection limit for the detection of PCV2 was 1.71 x 10(3) copies mL(-1). Moreover, the CLIA signal can be further enhanced by using hydroxylamine-amplified gold nanoparticles, and the limit of detection was as low as 2.67 x 10(2) copies mL(-1). Compared with conventional polymerase chain reaction (PCR), the proposed method has good sensitivity and reliability in analysis of 36 serum samples, and showed great potential in virus assays.