Gagging in dental patients can be disruptive to dental treatment and may be a barrier to patient care, preventing the provision of treatment and the wearing of prostheses. This article reviews the literature on the gagging problem from English-language peer-reviewed articles from the years 1940 to 2002 found by conducting an electronic search of PubMed, coupled with additional references from citations within the articles. Dentally relevant articles have been cited wherever evidence exists, and a balanced view given in situations where there is controversy. The first section considers the normal gag reflex and factors that may be associated with the etiology of gagging, including anatomical and iatrogenic factors, systemic disorders, and psychological conditions. A review of the management of patients with an exaggerated gag reflex follows and includes strategies to assist clinicians.