A non-randomized confirmatory trial was started in Japan to evaluate the efficacy of modified radical hysterectomy in patients with tumor diameter 2 cm or less FIGO Stage IB1 uterine cervical cancer, for which the current standard is radical hysterectomy. This study began in January 2013 and a total of 240 patients will be accrued from 37 institutions within 3 years. The primary endpoint is 5-year survival. The secondary endpoints are overall survival, relapse-free survival, local relapse-free survival, percent completion of modified radical hysterectomy, percent local relapse, percent pathological parametrial involvement, days until self-urination and residual urine disappearance, blood loss, operation time, percent post-operative radiation therapy, adverse events and severe adverse events. This trial was registered at the UMIN Clinical Trials Registry as UMIN 000009726 (http://www.umin.ac.jp/ctr/).