AIM: The aim of our study was to evaluate the incidence and timing of postoperative bleeding and to identify the potential aetiological factors of cervical hematomas complicating thyroid surgery. MATERIAL: Between September 2002 and December 2009, 2559 patients were operated on in Department of Surgery, University Hospital of Cagliari. 2257 total thyroidectomies, 191 total thyroidectomies associated to lymphadenectomy, 83 total thyroidectomies associated to parathyroidectomy, 24 thyroid lobectomies and 4 lobectomies associated to parathyroidectomy were performed. RESULTS: 35 Patients (1.36%) developed a postoperative hematoma, 32 of whom (1.25%) needed a surgical revision. Male sex seemed to have a greater risk: 13 men (2.79% of all males) vs. 19 women (0.90% of all female cases) had to undergo haemostasis revision (p=0.00204). 16 of 32 patients (50%) who underwent surgical revision had hypertension; incidence of hematoma was 2.09% in patients with hypertension and 0.89% in patients without it (p=0.02112) DISCUSSION: It is generally difficult to predict which patients are at risk for the development of a hematoma after thyroid surgery. The most intense postoperative monitoring is necessary during the first six hours but hematomas occurring after are not rare. CONCLUSIONS: Postoperative hematoma remains a rare but potentially life-threatening complication. Early recognition with immediate intervention is the key to the management of this complication. Because of the possibly long interval between the initial operation and the hematoma development, ambulatory and one-day thyroid surgery is not advisable