Introduction: Nowadays, use of non-pharmacological methods and complementary medicine to reduce pain intensity and anxiety during labor is increasing. Therefore, this study was performed with aim to compare the effects of Peppermint and Clove essential oil aroma on pain intensity and anxiety at first stage of labor.Methods: This clinical trial study was performed on 126 nulliparous women referred to Kamali hospital in Karaj, respectively divided into two groups of Peppermint and Clove (63 in each group) in 2014. Aromatherapy started from 3-4cm of cervix dilatation. In first group, 0.2 ml of essential oil of Peppermint and in second group, 0.2 ml of essential oil of Clove was stained to gas and attached to dresses collar of women and aromatherapy was repeated every half hour. Intensity of labor pain was measured in 3, 4cm, 5, 7cm and 8, 10cm of cervix dilatation and anxiety was measured in 3, 4cm and 8, 10cm of cervix dilatation. The data were collected through demographic-obstetric questionnaire, observation-examination checklist, Spielberger anxiety questionnaire and McGill Pain Ruler. The data were analyzed by statistical software (version 18), independent t-test, Chi-square and Mann-Whitney. PResults: After the intervention, there was a significant statistical difference between two groups of Peppermint and Clove in pain intensity and anxiety (P<0.001). It should be mentioned that in both groups, pain intensity decreased in cervical dilatations of 3, 4cm, 5, 7cm and 8, 10cm; but pain reduction in Clove aromatherapy group was more than Peppermint group. Also, obvious anxiety decreased in both groups in 3, 4cm and 8, 10cm cervical dilatations, but anxiety reduction in Clove aromatherapy group was more Peppermint group.Conclusion: Aromatherapy with essential oils of Clove compared to Peppermint leads to more reduction of pain and anxiety level during labor.