Aims: To compare the anesthetic efficacy of 1.8 mL of 2% lidocaine with 1:200,000 epinephrine, 4% articaine with 1:100,000 epinephrine, and 0.5% bupivacaine with 1:200,000 epinephrine on producing inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. Methods: A total of 91 adult patients who were actively experiencing mandibular molar pain were involved in this study. The patients were randomly divided into three groups on the basis of the anesthetic solution used. The first group received IANB with 1.8 mL of 2% lidocaine with 1:200,000 epinephrine, the second group received IANB with 4% articaine with 1:100,000 epinephrine, and the third group received IANB with 0.5% bupivacaine with 1:200,000 epinephrine. After 15 minutes of IANB, conventional endodontic access preparation was started. The pain during the treatment was noted on a Heft-Parker visual analog scale (HP VAS). The primary outcome measure was anesthetic success, and anesthesia was considered successful if the patient reported no pain or weak/mild pain (HP VAS score 55 mm) during endodontic treatment (pulp access and canal preparation procedures). The data were analyzed with one-way analysis of variance and chisquare test. Results: The anesthetic success rates of 2% lidocaine, 4% articaine, and 0.5% bupivacaine were 23%, 33%, and 17%, respectively. The differences were statistically insignificant (P > .05). Conclusion: The 2% lidocaine solution used for IANB had similar success rates when compared with 4% articaine and 0.5% bupivacaine. Keywords: anesthetic success, inferior alveolar nerve block, irreversible pulpitis, local anesthetic solutions