Observations that certain endocrine diseases occur more commonly in certain breeds of dog and cat have long suggested that genetic predispositions to disease exist. Examples of this include diabetes mellitus in the Burmese cat, hyperadrenocorticism in the miniature poodle, or hyperparathyroidism in the Keeshond. Understanding the genetic basis of endocrine disease is an exciting challenge and promises to deliver novel insights into pathophysiological mechanisms. Work is already underway to try to dissect the genetic basis of many human and veterinary endocrine diseases with the hope that such work may reveal new pathways and therapeutic or preventative opportunities. This presentation will be divided into several sections, beginning with an exploration of the way in which genes can affect disease risk, moving on to the techniques available for studying genotype-phenotype relationships, and concluding with some examples of genetic studies in canine and feline endocrine disease.