Thirty four varieties of sour cherries (Prunus cerasus) were investigated for their total antioxidant activity, Caco‐2 cancer cell proliferation inhibitory activity and effect on prostaglandin E2 (PGE2) production. Total phenolic content, oxygen radical absorbance capacity (ORAC) and cancer cell proliferation inhibitory activity of sour cherries were closely correlated but not PGE2 production. The cultivars ‘Birgitte × Böttermö’, ‘Fanal’ and ‘Tiki’ were the three cultivars with the highest ORAC values (180, 147 and 133 µmol TE/g, respectively) and inhibition against Caco‐2 cancer cell proliferation (74%, 79% and 73%, respectively). ‘Stevnsbaer Birgitte’ (22%) and ‘Stevnsbaer Viki’ (22%) inhibited PGE2 production with a similar potency as the positive controls indomethacin and NS‐398. Significant differences between cultivars in all bioactivity experiments indicated that selection of cultivars is important to obtain sour cherries with better potential health promoting effects. Copyright © 2012 John Wiley & Sons, Ltd.