In Central Europe, as well as in Poland many introduced spider species have been recorded in the past decades. Most of them are from areas with warm climate, and spreading mainly in synanthropic environment, rarely colonizing natural habitats. Results of research, presented in this paper extend the list of Polish synanthropic araneofauna by four species: Latrodectus mactans, Cheiracanthium mildei, Heteropoda venatoria and Heliophanus cf. apiatus. In addition, new findings of rare or rarely collected synanthropic spider species (Nesticella mogera, Scytodes thoracica, Psilochorus simoni, Uloborus plumipes, Parasteatoda tabulata, Steatoda triangulosa, Mermessus trilobatus, Ostearius melanopygius, Hasarius adansoni, Leptorchestes berolinensis, Pseudeuophrys lanigera) are discussed. Presented data enrich our knowledge about distribution of these species in Poland and show new pathways of potential expansion. For Uloborus plumipes and Hasarius adansoni presence of stable, permanent populations is shown. Findings of Mermessus trilobatus and Ostearius melanopygius in open country suggest that these alien species are gradually colonizing natural biotopes.