To evaluate the incidence of parametrial involvement in women with early‐stage cervical cancer with tumour <20 mm and with negative sentinel lymph nodes (SLN). Methods We reviewed the cases of all women who underwent radical hysterectomy and pelvic lymphadenectomy with SLN biopsy for invasive cervical cancer between April 2004 and December 2009. Parametrial involvement was defined as direct extension, nodal disease or spread through vascular channels. Results From the 204 women who underwent radical surgery with SLN biopsy, 63 (FIGO stage IA2‐10, IB1‐53) met the inclusion criteria: tumour <20 mm in the largest diameter regardless of the depth of stromal invasion (less or more than half stromal invasion) and negative sentinel lymph nodes. Median age was 44.3 years (range 24–72). Lymph–vascular space invasion was present in 25 women. The histology identified squamous carcinoma in 50 women, adenocarcinoma in 11 women and adenosquamous carcinoma in two women. Tumour grade 1 occurred in 41, grade 2 in 16 and grade 3 in 6 of the cases. No parametrial involvement was observed. The false negative rate of SLN biopsy was 0%. Conclusion No parametrial involvement was observed in women with early‐stage cervical cancer with tumour <20 mm in diameter and negative sentinel lymph nodes regardless of the presence of lymph–vascular space invasion, histology subtype and grade of the tumour. Radical removal of the parametrium in this low‐risk group is questionable.