This study aimed to evaluate the influence of The 2017 Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Data were collected from 2002–2007 with an indeterminate cytological report, and from 2010–2017 with a cytological report including categories III, IV and V of TBSRTC. Subsequently, both groups were compared regarding the established management, surgical incidence, and rate of malignancy. Among the 1458 patients who underwent fine–needle aspiration from 2002–2007, 154 (10.6%) had an indeterminate cytological report, while from 2010–2017, 138 out of 1147 (12%) had a cytological result compatible with categories III, IV and V. After further exclusion, of a total 135 cases pertaining to the pre–Bethesda group, 126 (93.3%) versus 94 out of 135 cases (69.6%) of the Bethesda group were referred for surgery (p<0.001). Restricted to the patients who underwent surgery, the malignancy rate before and after TBSRTC was 28.4% versus 55.3%, respectively (p=0.001). The malignancy rate within categories III, IV and V was 15/37, 10/20 and 17/19, respectively. The revised TBSRTC reduced the rate of unnecessary surgeries and honed the diagnostic accuracy for the detection of malignant nodules.