Recombinant human TSH (rhTSH) has revolutionized the care of patients with differentiated thyroid cancer. Since its approval for clinical use in 2001 in Europe (1998 in the USA), rhTSH has greatly enhanced the surveillance of these patients by allowing the avoidance of hypothyroidism for TSH stimulation. Previously, a hypothyroid state was required for TSH stimulated diagnostic whole-body radio-iodine scans (DxWBS) and thyroglobulin (Tg) levels. Patients generally prefer rhTSH as a mechanism for TSH stimulation because symptoms of hypothyroidism can be completely avoided. Currently, rhTSH is only approved for diagnostic monitoring of differentiated thyroid cancer patients. There are many other potential uses for rhTSH, including facilitation of treatment of patients with thyroid cancer and nodular goiter. The diagnostic and therapeutic role of rhTSH in patients with differentiated thyroid cancer and nodular goiter will be discussed in this review.