The Act on Nature Conservation of 16.04.2004 (Official Journal, 2004, No 92, item 880) imposes on private individuals the duty to register some animals. The data collected by Kraków municipal authorities and delivered to the Poison Information Centre (Colleglum Medicum, Jagiellonian University) indicate that there are following species in private hands in the city and its surroundings: 11 individuals of Naja naja, 2--Hydrodynates gigas and 55-- Dendrobates spp. According to these information the employees of the PIC elaborated the advice on the treatment of specific animals' poisoning. In the period May 2003 - May 2004 (before the above Act came into force) there were 143 individuals from Brachypelma genus and 3 scorpions (Pandinus imperator) registered in Krakow. These species produce venoms which take local effect. According to art. 64 (1) of the above Act it is compulsory to register amphibians, reptiles, birds and mammals. However, it would be desirable to introduce the duty to register also dangerous species of invertebrates and fishes. It would provide the complete list of poisonous animals kept in private hands. Thus, it would be possible to estimate any possible threats and to elaborate adequate treatment in case of specific animals' poisoning.