Objective: This prospective, block randomized clinical trial was conducted to evaluate the effect of aromatherapy on the success rate of inferior alveolar nerve block (IANB) in teeth with irreversible pulpitis. Method and materials: In this clinical trial, 46 patients fulfilling the inclusion criteria were randomly divided into two equal groups: group I (n = 22) received IANB in a closed operatory without any fragrance, whereas group II (n = 24) received IANB in a separate closed operatory saturated with lavender fragrance using a candle warmer. The modified dental anxiety scale (MDAS) for anxiety and visual analog scale (VAS) for pain were recorded preoperatively as well as during access cavity preparation. For MDAS, a total score of more than 18 was considered as tremendously anxious or dental phobic. No or mild pain on VAS was considered as success. Data were analyzed using paired t test and independent sample t test. P .05 was considered as statistically significant. Results: Difference in mean VAS (P = .749) and MDAS (P = 1.000) between both the groups was statistically nonsignificant. However there was a statistically significant difference in mean VAS (P = .000) and MDAS (P = .001) during access opening. Conclusion: Lavender aromatherapy can be used successfully to alleviate dental anxiety as well as to increase the anesthetic success rate of IANB in teeth with irreversible pulpitis. Keywords: aromatherapy, inferior alveolar nerve block, irreversible pulpitis, lavender