Radical hysterectomy and pelvic lymphadenectomy is recommended for stage Ia2-Ib1 cervical cancer while parametrial involvement (PI) is rare. Our aim was to evaluate criteria to select women with low risk of PI that could benefit from simple hysterectomy. Factors associated with low risk of PI were analyzed in a series of 37 patients with stage Ia2-Ib1 cervical cancer undergoing radical hysterectomy and sentinel lymph node procedure from 2003 to 2008. PI was associated with tumor size (p<0.001) and lymphovascular space invasion (LVSI) (p=0.007). PI was found in 4.5% of patients with tumor size <or=2 cm versus 33% with tumor size >2 cm (p=0.04). The negative predictive value was 100% for absence of LVSI (95% CI: 0.83-1) and for combinations: tumor size <or=2 cm and SN negative (95% CI: 1-1), tumor size <or=2 cm and no LVSI (95% CI: 0.86-1), tumor size <or=2 cm and tumor grade 1-2 and no LVSI (95% CI: 0.82-1), and tumor size <or=2 cm and PLN negative and no LVSI (95% CI: 0.83-1). Among various combinations, a tumor size <or=2 cm and absence of LVSI appears the most relevant to predict parametrial status.