The present invention relates to humanized Her3 specific antibodies and antigen-binding portions thereof. Nucleic acid molecules encoding the Her3 antibodies as well as methods of use thereof are also disclosed. Also included are pharmaceutical compositions comprising these antibodies and methods of using the antibodies and compositions thereof for treatment and diagnosis of pathological hyperproliferative oncogenic disorders associated with aberrant expression of Her3 or Her2 including aberrant activation of each of these receptors.