Mandibular molar teeth with acute irreversible pulpitis pose challenges in single visit root canal treatment - (i) success of local anaesthesia and (ii) post-operative pain. One hundred and twenty-six patients with pain associated with carious mandibular molar teeth were enrolled. All patients were administered 10 mg of ketorolac tromethamine prior to local anaesthesia. Local anesthetics used were 2% lignocaine with 1:80 000 adrenaline and 4% articaine with 1:100 000 adrenaline. Three irrigation solutions were used - saline, 3% sodium hypochlorite and dexamethasone. Mean intra-operative pain scores for the lignocaine and articaine groups were 4.33 (±2.58) and 4.22 (±2.88), respectively. There was a statistically significant difference (P = 0.000) in post-operative pain incidence between the lignocaine and articaine groups with 16.7% (10 patients) and 49.2% (29 patients), respectively. Pre-operative ketorolac tromethamine was not effective in reducing the intra-operative pain incidence. However, it was effective in controlling post-operative pain with lignocaine anesthetic group.