The spectrum of orbital inflammatory disease (OID) ranges broadly from specific disease diagnoses, for example, Wegener's granulomatosis or sarcoidosis, to nonspecific inflammation which may involve one or multiple structures of the orbit. Mimics of idiopathic OID must be considered in a comprehensive differential diagnosis and include malignancies, congenital mass lesions, infectious diseases, and occult or distant trauma. Idiopathic OID may be secondary to an underlying systemic inflammatory disease, which must be diagnosed in order to develop a comprehensive therapeutic plan, or may represent localized pathologic processes without systemic involvement. Evaluation of the patient with suspected OID must include a careful history, physical examination, directed laboratory, and radiologic studies, and may sometimes require tissue for diagnostic studies. Therapeutic options for inflammatory diseases are expanding as biologically targeted agents become available that act on specific segments of the inflammatory cascades. The purpose of this paper is to provide a framework for the evaluation and management of patients with the spectrum of diseases known as OID and to discuss some of the new advances in immunologic monitoring and targeted immune therapies that will likely play an increasingly important role in the care of these patients.