Purpose: This research was done to compare obstetric pain, anxiety and cervical dilatation between an epidural analgesia group and a control group. Methods: Participants were assigned to the experimental or control group depending on their decisions for pain relief. Subjective / objective obstetric pain, anxiety level and cervical dilatation were measured and ANOVA was used for comparison of groups and paired t-test to make pre-post comparisons. Results: Homogeneity of pain, anxiety and cervical dilatation were assessed at the latent phase. Cervical dilatation was larger in the control group than the experimental group, at both the active and the transitional phase (F=22.9, p<.001; F=39.9, p<.001 respectively). The degree of pain and anxiety were not significantly different between the groups. Within the experimental group, subjective / objective pain and anxiety level were significantly lower post-analgesia compared to pre-analgesia in the active phase. All variables, except for sweating in the objective pain measurement, changed significantly at the transient phase. Conclusion: The results of this evidence-based research indicate that epidural analgesia while effective in relieving pain and anxiety may have an adverse effect on the cervix during labor stage I. Epidural analgesia should be used carefully during cervical dilatation in labor stage I.