The effect of A rgentine ant (Linepithema humile) invasion on the dispersal -predation balance of non-myrmecochorous seeds by ants and vertebrates is analyzed. Three Papilionaceae, Calicotome spinosa, Psoralea bituminosa, and Spartium junceum, were studied.The seeds were made available in field trials during 48 hour periods using ant and vertebrateexclusions in zones invaded by L. humileand non-invaded zones. The Argentine ant invasionresulted in the displacement of most of the native ant species, including the single seed predatorant in the non-invaded zone, Messor bouvieri. Consequently, the level of seed removal by antswas lower in the invaded zone for the three seed species. This could produce two oppositee ffects for the plant: a positive reduction of seed predation and a negative loss of seed dispersaldue to diszoochory (the seed dispersal performed by seed eating ants). The three studied species suffered different intensities of seed removal by ants in the non-invaded zone, so they would bea ffected to varying degrees after the invasion. The level of seed removal by vertebrates waslower than seed removal by ants and was similar in the invaded and non-invaded zones and forthe three seed species.