The aim of this work was to evaluate the effect of stilbenes from different cultivars of Vitis vinifera on tumour proliferation. Extracts were obtained from elicited V. vinifera cell cultures and characterised by HPLC/DAD/MS. Cell growth was evaluated in four human cancer cell lines and in normal human fibroblasts. The cells were exposed to the extracts or to trans-resveratrol, used as reference molecule, for 48 h, at 1–10 mM concentrations of total stilbenoids. All the extracts exhibited antiproliferative activity, mediated by modulation of the cell cycle and induction of cytotoxicity in cancer but not in normal cell lines, and positively correlated with the content in dimeric stilbenoids. The Alphonse Lavalle´e extract was the most active, and the obtained stilbenoid fraction resulted 8–10 times more active than trans-resveratrol. Extracts from V. vinifera cell cultures could represent new sources of active stilbenoid compounds to be further assayed in in vivo studies for their antitumoural properties.