Neuroendocrine networks interact with sleep-disordered breathing (SDB) bidirectionally. This is typified by the interaction with the hypothalamopituitary gonadal axis in men and women whereby gonadal hormones acutely alter sleep breathing and, conversely, SDB can suppress gonadal function. CPAP effectively improves testicular function. The effect of OSA on growth hormone, prolactin, and adrenal and thyroidal function appears to be more modest, but available studies are largely uncontrolled (lacking obesity-matched controls for observational studies, or sham-CPAP controls for interventional studies) or small in sample size. Clinicians should be aware that SDB can impair neuroendocrine function and also that SDB is common in certain endocrine disorders such as acromegaly, Cushing disease, and myxoedema. The mechanisms driving these interactions require further elucidation.