Ion exchange is a major technique for boron removal from seawater using specific ion-exchange resins. The aim of this study was to compare two techniques using ion-exchange resins (column and hybrid ion-exchange microfiltration) for boron removal. For that, model boron solutions were used and ion-exchange resin with different size (unsieved, sieved at 500 and 600 mu m, ground and sieved at 40 and 60 mu m) for three commercial resins (Amberlite IRA743, Diaion CBR05, Purolite S108) in batch, column, and in an hybrid ion-exchange/microfiltration system. In batch, an important increase in kinetics was observed for smaller resins (40-60 mu m and <500 mu m). In column, delayed and sharper breakthrough curves were observed for resins with size <500 mu m. With the hybrid system, the breakthrough curve observed at optimal conditions and the 40-60 mu m Amberlite IRA743 resin was similar to the one obtained in a column with the <500 mu m resin; however, the flow rate with the hybrid system was 20 times higher. Overall, the resin size had a major effect on the ion-exchange resin efficacy for boron removal, and the ion-exchange resin/microfiltration process that uses resins with much smaller size is promising.