Objective: Fine needle aspiration (FNA) cytology with thyroglobulin wash (TG-W) testing is recommended for follow-up of patients with differentiated thyroid carcinoma (DTC). The goal of this retrospective study was to determine if TG-W results contributed to the management of cases with positive FNA cytology. Study Design: We reviewed data on patients with positive and suspicious cytology results, undergoing lymph node or thyroid bed FNA with TG-W testing as part of the preoperative or follow-up investigation of histologically proven DTC in our institution and from the literature. Results: Of 30 positive/suspicious lymph node and thyroid bed FNAs in our institution, 22 (73%) had an elevated (>1 ng/ml) TG-W level. Seven of 8 TG-W-negative cases had DTC on follow-up. Of 577 cytology-positive/suspicious FNAs in the literature, 557 (97%) showed TG-W-positive results. Fourteen of 20 TG-W-negative cases had DTC on follow-up. All patients in retrospective and literature review groups with positive and suspicious FNA cytology and available follow-up were treated for recurrent or metastatic disease regardless of TG-W results. Conclusion: Observations of both our and other institutions support a recommendation of reflex FNA TG-W testing only for cases with negative or indeterminate cytology results.