Gulls have been shown to be seed dispersal vectors; however, knowledge is needed about the effectiveness and the distance achieved by seeds dispersed by gulls, especially in coastal areas and small islands where gulls can be more relevant. In the Balearic Islands (Spain), yellow-legged gulls Larus michahellis eat and regurgitate a large number of olives, both large domestic (Olea europaea) and small wild fruits (var. sylvestris). By comparing the size of seeds in gull pellets with that of the olive trees around the colonies, we found that domestic seeds were transported from large islands to the small ones. Modelling based on GPS tracking and seed retention time indicated dispersal distances for domestic olives larger than for wild seeds. Most olives (88 %) were dispersed within islands, 8.2 % of wild seeds were dispersed from a small (Dragonera) to a major island (Mallorca), while 10.4 % of domestic olives were dispersed in the opposite direction. Daily foraging movement of gulls and olive availability might affect differentially the seed dispersal pattern of the two olive ecotypes. Although gulls are not the only birds dispersing olives, they may influence olive tree distribution on island ecosystems, where other large frugivores are absent.