The appropriateness of using honeycomb seals in steam turbines is examined and the effective efficiency of using them is evaluated. It is shown that using honeycomb seals in the regulated stages and, in some cases, in the first unregulated stages, for the pressure in the high pressure cylinder, may be accompanied by losses of stability of the unit and the appearance of low frequency vibrations. Some examples of designs for seals in steam turbines with long lifetimes and enhanced antivibration properties proposed by leading foreign companies are discussed.