The invention provides humanized anti-Siglec-8 antibodies and their use in treating and preventing eosinophil-mediated disorders and/or mast cell-mediated disorders, as well as compositions and kits comprising the humanized anti-Siglec-8 antibodies.Linvention concerne des anticorps humanisés anti-Siglec-8 et leur utilisation pour le traitement et la prévention de troubles médiés par les éosinophiles et/ou les mastocytes, ainsi que des compositions et des trousses contenant lesdits anticorps humanisés anti-Siglec-8.