Naturally occurring hyperadrenocorticism is a multisystemic disorder resulting from excessive production of cortisol by the adrenal cortex. Hyperadrenocorticism is caused by either excessive pituitary ACTH secretion, as in pituitary-dependent hyperadrenocorticism (PDH), or an autonomously functioning tumor of the adrenal cortex (AT). Primary adrenocortical neoplasia has been diagnosed in 10 to 20% of dogs with hyperadrenocorticism. The prevalence of adenomas and carcinomas in dogs with functioning adrenocortical tumors is approximately equal, and the right and left glands appear to be involved with equal frequency. Bilateral adrenocortical tumors resulting in hyperadrenocorticism are exceedingly rare in dogs. In a retrospective study conducted between 1983 and 1988 of 41 dogs with hyperadrenocorticism caused by adrenocortical neoplasia, 3 dogs (7%) were found to have bilateral adrenocortical neoplasia. The following is a case report of a dog that was diagnosed with hyperadrenocorticism due to bilateral adrenocortical tumors and some of the associated complications.