Micrurus envenoming is a medical emergency that requires the rapid use of antivenom and occasionally the use of pharmacological and mechanical support due de respiratory paralysis that can occur. The antivenom is the only specific treatment and the most important tool to treat the envenomed patients, specially, those treated in peripheral centers where other kind of support apart the antivenom is not available. By this reason the antivenom is essential for the treatment of this type of envenomation. For the antivenom production is necessary to obtain the venom, which is a difficult task due the scarcity of snakes in nature in Argentina and due the short survival of the specimens in captivity, which limits the venom obtaining and consequently the antivenom production. In order to know the historical income of snakes to our serpentarium and the venom production, we analyzed the records of reception of Micrurus specimens and the their venom production in the INPB during the period 1991-2020. Even though this is a preliminary report based in historical registers, initial data provide a draft idea of the coral snakes reception and the Micrurus venom production. In this period was registered the reception of 322 specimens (around 11/year, Md 7, min. 0, max. 76) and in 7 years, no snakes were received. The reception drastically decreased, in the last three decades were received 220 (1991-2000), 89 (2001-2010) and 13 (2011-2020) coral snakes. The number of Micrurus used by milking session varied from 1 to 22 snakes (Md 4), with around 2 milking sessions/year. The individual venom yield varied from 1 to 40 mg (the last in only one individual case). The yield of venom/snake (mg of venom/number of snakes milked) was 8.6 ± 5.5 (Md 8, min 1 max. 26, 25% 4, 75% 11.7). The number of snakes received in the serpentarium decreased from a mean of 34 snakes/year in the period 1991-1995 to 1 snake/year in the period 2016-2020. Despite the difficult in venom obtaining, the Micrurus antivenom was produced with continuity and no deaths by coral snake bites were registered in the last 25 years. The decrease in the number of coral snakes received in the last years may impairs the antivenom production.