Mercury isotopes are now broadly applied in various fields of science and technology. They are used in medicine, nuclear physics investigations, RF standards, nuclear gyroscopes, mercury analysing devices etc. One of the most promising applications is the use of weakly enriched (up to 3%) isotope196Hg in fluorescent lamps for enhancing their light efficiency. Besides, the application of201Hg and202Hg as the target material for the production at low-energy cyclotrons of one of the most consumed201Tl isotope in medicine seems to be perspective. Various methods were proposed and examined for the separation of mercury isotopes. There are: electromagnetic, photochemical, centrifugal, laser, photoionizing method etc. But only two of them were effective for the mercury isotope separation: electromagnetic and photochemical ones. This paper presents a review of the experimental results on separation of various mercury isotopes by different methods.