Humanized anti-CD11 a antibodies and various uses therefor are disclosed. Thehumanized anti-CD11aantibody may bind specifically to human CD11a I-domain, have an IC50(nM) valueof no morethan about 1nM for preventing adhesion of Jurkat cells to normal humanepidermal keratinocytes expressingICAM-1, and/or an IC50 (nM) value of no more than about 1nM in the mixedlymphocyte response assay.