The present invention relates to antibodies and antigen-binding portions thereof that specifically bind to CD40, preferably human CD40, and that function as CD40 agonists. The invention also relates to human anti-CD40 antibodies and antigen-binding portions thereof. The invention also relates to antibodies that are chimeric, bispecific, derivatized, single chain antibodies or portions of fusion proteins. The invention also relates to isolated heavy and light chain immunoglobulins derived from human anti-CD40 antibodies and nucleic acid molecules encoding such immunoglobulins. The present invention also relates to methods of making human anti-CD40 antibodies, compositions comprising these antibodies and methods of using the antibodies and compositions for diagnosis and treatment. The invention also provides gene therapy methods using nucleic acid molecules encoding the heavy and/or light immunoglobulin molecules that comprise the human anti-CD40 antibodies. The invention also relates to transgenic animals comprising nucleic acid molecules of the present invention.