Two Hahns Macaws (Ara nobilis nobilis), three and nine-month-old, with a three-weeks history of weight loss and anorexia were diagnosed presumptively with proventricular dilatation disease (PDD) by radiographic examination. The birds were treated with antimicrobials, analgesics, and fluid administration. However, these birds died three weeks after the first signs of PDD. At necropsy, the birds had severely dilated proventriculus, severe pectoral muscles atrophy, and blood vessels congestion on cortex of cerebrum. The partial matrix gene of avian bornavirus (ABV) was detected by RT-PCR from tissues of the brain, feather calami, and proventiculus of each PDD-suspected birds. This report describes the first detection of ABV in PDD-suspected Hahns Macaw in Korea.