No prophylactic pharmacological intervention has proven efficacy in relieving pain during or after the insertion of levonorgestrel-releasing intrauterine system (LNG-IUS), only in reducing pain associated with the tenaculum. It is known that the nulligravida women have 3 times more chance of presenting moderate / severe pain associated to LNG-IUS placement. A previous study showed that injectable intracervical anesthesia reduced the risk of moderate/severe pain by 40%. However, the anesthetic dose was small (36 mg of lidocaine) and the study did not evaluate only nulligravida women which are potential candidates for most pain relief benefit. Thus, the primary aim of this study is to evaluate the effect of intracervical anesthesia on pain scores immediately following LNG-IUS insertion in nulligravida women.