Based to a great extent upon mainly anecdotal case reports and theory, there is a general acceptance that patients on long-term systemic steroid medication should receive supplementary glucocorticoids or "steroid cover" when undergoing certain types of stressful treatment including dentistry. The theoretical basis to this practice is that exogenous steroids suppress adrenal function to an extent that insufficient levels of cortisol can be produced in response to stress, posing the risk of acute adrenal crisis with hypotension and collapse. The purpose of this paper is to review relevant literature and propose clinical guidelines for dental practitioners. Of numerous reported cases of adrenal crisis following procedural interventions, few stand up to critical evaluation. Other reviewers have reached similar conclusions. A number of studies confirm the low likelihood of significant adrenal insufficiency even following major surgical procedures. Various authors have suggested modified guidelines for management of patients on steroid medications. Patients on long-term steroid medication do not require supplementary "steroid cover" for routine dentistry, including minor surgical procedures, under local anaesthesia. Patients undergoing general anaesthesia for surgical procedures may require supplementary steroids dependent upon the dose of steroid and duration of treatment.