A 25-year-old patient treated for relapsing remitting multiple sclerosis (RRMS) with natalizumab had a rapid progression of a low grade squamous intraepithelial lesion to a FIGO stage 1B1 squamous cell carcinoma of the uterine cervix within 2 years. She was treated with radical hysterectomy and pelvic lymphadenectomy and subsequently developed a vault recurrence within 2 years. The recurrence was treated with definitive synchronous chemo-radiotherapy and she has been disease free for 7 years. This case and existing evidence on increased risk of developing cervical dysplasia under natalizumab show that MS patients under immunosuppressive therapy require close annual cervical screening with immediate investigation of abnormal test results.