Cross-efficiency　evaluation　is　an　effective　way　of　ranking　decision　making　units　(DMUs)　in　data　envelopment　analysis　(DEA).　Existing　approaches　for　cross-efficiency　evaluation　are　mainly　focused　on　the　calculation　of　cross-efficiency　matrix,　but　pay　little　attention　to　the　aggregation　of　the　efficiencies　in　the　cross-efficiency　matrix.　The　most　widely　used　approach　is　to　aggregate　the　efficiencies　in　each　row　or　column　in　the　cross-efficiency　matrix　with　equal　weights　into　an　average　cross-efficiency　score　for　each　DMU　and　view　it　as　the　overall　performance　measurement　of　the　DMU.　This　paper　focuses　on　the　aggregation　process　of　the　efficiencies　in　the　cross-efficiency　matrix　and　proposes　the　use　of　ordered　weighted　averaging　(OWA)　operator　weights　for　cross-efficiency　aggregation.　The　use　of　OWA　operator　weights　for　cross-efficiency　aggregation　allows　the　decision　maker　(DM)＇s　optimism　level　towards　the　best　relative　efficiencies,　characterized　by　an　orness　degree,　to　be　taken　into　consideration　in　the　final　overall　efficiency　assessment　and　particularly　in　the　selection　of　the　best　DMU.　©　2010　Elsevier　Ltd.