One of the research lines developed in our laboratory is focused on the study of the bioactivity of natural substances. Resveratrol (RV) is a polyphenol nonflavonoid compound present in a number of plant species but mainly in the berries of the red grape Vitis vinifera. The powerful antioxidant action of this molecule is well documented. In this work we evaluated the effects of this substance by adopting diverse experimental strategies. In particular, we studied the effects on cell vitality and cycle by MTT and cytofluorimetric assays. In addition, we explored the action of RV on the cell membrane by a well-consolidated biophysical approach: electrorotation. This technique allows assessment of the structure/function of the cell membrane. The results presented here demonstrate that RV shows a modest effect on the biological properties of the cell in terms of cytotoxicity and cell cycle alterations. On the contrary, a significant effect on the membrane structure/function was observed, consisting of an enhanced intramembrane ion transport. The implications and interpretation of these membrane alterations are discussed.