Background　Etomidate, a carboxylated imidazole-containing compound, is chemically different from any other drugs used for intravenous anesthesia. It also has hypnotic property without perturbing hemodynamics.　Objective　To review the pharmacology, clinical application and side effects of etomidate.　Content　Pharmacologically, etomidate potentiates γ-aminobutyric acid(GABA) ergic synaptic transmission directly by activating GABAA receptors and indirectly by enhancing the affinity of GABAA receptors to GABA, inhibits biological effects of cortisol, and activates 2B adrenoceptor. Thus, it has been used for several clinical applications, including fast induction of anesthesia, tranquilization, anti-shock, antiseptics, and maintaining normal hemodynamics in major surgeries, etc. Accompanying these therapeutic effects, etomidate causes some side-effects, such as, inhibition of the synthesis of cortisol, muscle spasm, cognitive deficits, and vomiting.　Trend　Because of its fast onset property for anesthesia induction and minor effect on cardiovascular system, etomidate has been widely used in major surgeries, however, for the safety issue, the practitioners should be aware of its adverse effects.