Introduction: to evaluate the efficacy of inferior alveolar nerve block (IANB), Gow-Gates nerve block (GGNB), and their combination in patients with irreversible pulpitis. Methods: One hundred fifty subjects with irreversible pulpitis of a mandibular molar were selected. subjects randomly received two IANB injections or two GGNB injections or their combination of 1.8 mL 2% lidocaine with 1:100,000 epinephrine. Success was specified as no or mild pain on the basis of Heft-Parker visual analogue scale recordings up on the access cavity preparation or initial instrumentation. Data were analyzed by Kruskal-Wallis, and ANOVA tests.