[Summary]: The Bulgarian Entomological Society was founded on 6th January 1909 by seven Bulgarian entomologists with Prof. Porfirij Bachmetjew at the head. It was most active in the years between the First and the Second World War. Dr Iwan Buresch, Member of the Bulgarian Academy of Sciences, led the Society for 30 years. The meetings were held every week with up to 157 reports yearly. The increase of the member number up to 66 is shown on Fig. 8. Twelve volumes (1924-1942) of the first reputable entomological journal in Bulgaria — Bulletin of the Bulgarian Entomological Society (Izvestiya na Balgarskoto entomologichno druzhestvo) have been published with a total of 2283 pages. The entomofaunistics and the applied entomology were equally presented in the scientific activity of the Society. The Bulgarian was the only entomological society in the Balkan Peninsula during the first 20 years of its existence. Up to 65 field trips yearly have been organized. A separate library at the Society existed till 1929 and took up to 54 foreign journals. The associated entomologists have been published up to 87 papers yearly. The activity declined gradually after the Second World War and the Society terminated its work in 1951. Four decades later the Bulgarian Entomological Society was restored again in 1992. It organized four national conferences of entomology every other year. The papers of the first three conferences were printed in separate proceedings. Since 1995 the Society began to publish a new journal — Acta entomologica bulgarica. The organizing of the Fifth National Conference of Entomology with international participation is coming in June 1999.