The present invention relates to anti-IL13 antibodies that bind specifically and with high affinity to both glycosylated and non-glycosylated human IL13, does not bind mouse IL13, and neutralize human IL13 activity at an approximate molar ratio of 1:2 (MAb:IL13). The invention also relates to the use of these antibodies in the treatment of IL13-mediated diseases, such as allergic disease, including asthma, allergic asthma, non-allergic (intrinsic) asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, eczema, urticaria, food allergies, chronic obstructive pulmonary disease, ulcerative colitis, RSV infection, uveitis, scleroderma, and osteoporosis.L'invention porte sur le traitement de troubles néoplastiques qui dépendent de IL13, consistant à administrer de nouveaux anticorps anti-IL13. Cette invention se rapporte également au diagnostic de tumeurs ou du cancer au moyen des anticorps susmentionnés afin de détecter la surexpression de IL13 chez un patient.