To evaluate overtreatment with the 'see-and-treat' approach in patients with high-grade squamous cervical cytology, and identify the clinical factors associated with overtreatment. Patients with high-grade squamous intra-epithelial lesion (HSIL) cytology undergoing colposcopy and loop electrosurgical excision procedure (LEEP) in a single visit or the 'see-and-treat' approach from January 2005 to December 2019 were reviewed retrospectively. The overtreatment rate and complications following LEEP were explored. In total, 220 cases were identified. The overtreatment rate was 11.4%, and surgical complications were haemorrhage (n=3, 1.36%) and infection (n=9, 4.09%). On univariable analysis, factors associated with overtreatment were current cytological result and colposcopic impression. On multi-variable analysis, current cytological result of non-HSIL compared with HSIL/cancer, and colposcopic diagnosis of low-grade lesion or normal compared with high-grade lesion or cancer had adjusted odds ratios of 13.81 [95% confidence interval (CI) 1.23-155.20; p=0.033] and 3.58 (95% CI 1.32-9.74; p=0.013), respectively. The overtreatment rate with the 'see-and-treat' approach was 11.4%. Independent factors associated with overtreatment were current cervical cytological result of non-HSIL, and low-grade or normal colposcopic diagnosis.