Objective: Although the experience of pain is multidimentional, and general psychological factors such as anxiety are found to be associated with acute pain, it is necessary to investigate individual emotional variables such as emotional reactivity (ER). The aim of this study was to determine if increased ER is associated with pain during intrauterine device (IUD) insertion even without existing pre-procedure anxiety. Study Design: Prospective cohort study. Methods: We measured the anxiety level in 237 women using the Beck Anxiety Inventory and the ER level using the Emotional Reactivity Scale (ERS) at Zonguldak Maternity Hospital between November 2018 and March 2019. The women rated their pain during IUD insertion. To evaluate the role of ER in the prediction of pain during IUD insertion, we divided the women into subgroups based on the presence of anxiety and level of pain during IUD insertion. Results: ER was higher in women who had anxiety and moderate-severe pain (p = 0.001). In women who were not anxious, ER was higher in those who had moderate-severe anticipated pain or IUD insertion pain than in those who had mild anticipated pain or IUD insertion pain (p = 0.001). In anxious women, the ERS cut-off value was ˃ 34 for predicting the level of pain whereas in non-anxious women, it was ˃ 25. Conclusion: ER is a psychological factor strongly associated with pain at IUD insertion and the ERS appears to be a beneficial tool for detecting ER for this purpose. Health professionals should be aware that psychological factors could contribute to perceived pain more than physiological factors do. Implications: ER is a psychological factor associated with pain at IUD insertion and increased ER is a predictive factor for pain during IUD insertion even without existing pre-procedure anxiety. ERS seems to be a beneficial tool for detecting ER.