During 1995-2000, the authors evaluated necrotic disease of 4900 individuals of beech in the growth phase of natural seeding in 44 selected localities in Slovakia. Frequency of necrotic disease in natural seeding under the parent stand showed a wide range of 7.0-51.0%. The necroses of the young beeches stems contributed at most (7.0-46.0%) to the total frequency of necroses. In the virgin stands, the frequency of young beeches ranged from 7.0 to 35%. In the stands showing differenced stand density within the same locality, we have found out that necroses frequency continuously decreases with increasing stand density (from 97.0 on a clearing to 35.0% in a stand showing stand density of 0.9). From the view point of partial elimination and slowing down of development of necrotic disease in natural seeding we consider the respecting of principles of careful timber exploitation and consequent hygiene after stand cutting to be essential preventive measure. The beech stands should be regenerated in conditions of shelter-wood cutting.