Fluorinated nucleoside analogues are known as antitumor, antiviral and chemotherapeutic agents, although the antioxidant activity of this kind of molecules is not yet investigated. In this study we have tested the antioxidant activity of a series of modified pyrano-nucleoside analogues using three in vitro assays. Firstly, the antioxidant capacity of the products was assessed using the DPPH assay and secondly, in order to examine the ability of the products to protect DNA from the activity of reactive oxygen species (ROS), a peroxyl radical (ROO center dot) and a hydroxyl radical (OH center dot) induced DNA strand scission assay were used. None of the molecules showed the ability to scavenge DPPH radical and prevent OH center dot induced DNA strand breakage. Although, most of the tested nucleoside analogues, had the ability to prevent ROO center dot induced DNA damage.