The present invention encompasses prostaglandin E2 (PGE2) binding proteins. The invention relates to antibodies that are wild-type, chimeric, CDR grafted and humanized. Preferred antibodies have high affinity for prostaglandin E2 and neutralize prostaglandin E2 activity in vitro and in vivo. An antibody of the invention can be a full-length antibody, or an antigen-binding portion thereof. Methods of making and methods of using the antibodies of the invention are also provided. The antibodies, or antigen-binding portions, of the invention are useful for detecting prostaglandin E2 and for inhibiting prostaglandin E2 activity, e.g., in a human subject suffering from a disorder in which prostaglandin E2 activity is detrimental.