SummaryOrphan nuclear receptors provide a unique resource for uncovering novel regulatory systems that impact human health and provide excellent drug targets for a variety of human diseases. Ligands of nuclear receptors have been used in a number of important therapeutic areas, such as breast cancers, skin disorders, and diabetes. Orphan nuclear receptors, therefore, represent a tremendous opportunity in understanding and treating human diseases. This review highlights advances and potentials of using orphan nuclear receptors, in particular PPARs, Nurr1, RORs, and TLX as targets for drug discovery in diabetes and obesity, neurodegenerative diseases, and other related disorders.