Dedicated to Professor Grzegorz Mlostoń on the occasion of his 70 th birthdayThe antioxidant properties and the cytotoxicity of differently substituted β-hydroxyand β-amino dialkyl and alkyl-aryl tellurides, prepared through ring-opening reactions of epoxides and aziridines with selenium-or tellurium-centered nucleophiles, have been investigated on normal human dermal fibroblasts. Most of the studied compounds exhibited a low cytotoxicity and a number of them proved to be non-toxic, not showing any effect on cell viability even at the highest concentration used (100 μM). The obtained results showed a significant antioxidant potential of the selected organotellurium compounds, particularly evident under conditions of exogenously induced oxidative stress. The antioxidant activity of selenium-containing analogues of active tellurides has also been evaluated on cells, highlighting that the replacement of Se with Te brought about a significant increase in the peroxidase activity.