This is the first detailed contribution on the arachnid fauna from heated greenhouses in the Botanical Garden of the P.J. Šafárik University in Košice (Slovakia). Over ten years 62 spider taxa in 21 families were found. Two spiders, Mermessus trilobatus (Emerton, 1882) and Hasarius adansoni (Audouin, 1826), were recorded in Slovakia for the first time. Another interesting record was the cellar spider Hoplopholcus sp. and a new locality for the exotic spiders Coleosoma floridanum Banks, 1900 and Triaeris stenaspis Simon, 1891 was discovered. Additionally, a short survey of other arachnids (except Acari) was done. A single specimen of a provisionally identifiable palpigrade species (cf. Eukoenenia florenciae), one harvestmen species, Opilio canestrinii (Thorell, 1876), and four pseudoscorpion species were recorded. The rare pseudoscorpion species Chthonius ressli Beier, 1956 was collected for the second time in Slovakia.