Complete situs inversus is a rare congenital condition that is characterized by the development of the thoracic and abdominal viscera in a mirror image to their normal orientation. This study describes this condition in 2 dogs: an 8-year-old male dalmatian that was originally evaluated for cystitis and a 3-year-old male crossbreed Pekinese that had a routine echographic study. In dogs, most of the reported cases were associated with the Kartagener syndrome, but our patients had no evidences of this ciliary disorder.