Background: The present study was conducted for analysing anesthetic Efficacy of 4% Articaine and 2% Lidocaine for Buccal Infiltration in Adult Patients with Irreversible Pulpitis of Maxillary First Molar. Materials & methods: A total of 100 patients were enrolled in the present study. Only those patients were enrolled which had moderate to severe pain in maxillary first molar tooth along with a positive response to cold test. All the patients were randomized into two study groups as follow:Group A: 4% Articaine group, and Group B: 2% Lidocaine group. Visual Analog scale (VAS) was used for assessment of pain. It measured pain on a scale of 0 to 10 with 0 indicating no pain and 10 indicating most severe pain. Measurement of tooth length was done on the basis of preoperative radiographs. Aspiration was performed and aesthetic solution was deposited according to the respective groups. After a time interval of six min post injection of anesthetic agent, the patients were asked to rate their pain on VAS. The access opening (AO) was initiated only when the patient experienced either no pain. All the results were recorded in Microsoft excel sheet and were subjected to statistical analysis using SPSS software. Results: Mean VAS among patients of group A and group B was 1.9 and 2.8 respectively. Success rate among patients of group A and group B was 94 percent and 84 percent respectively. Significantly better results were obtained among patients of group A in comparison to patients of group B. Conclusion: The anesthetic efficacy of2% lidocaine with 1:80,000 epinephrine was less as compared to 4% articaine with 1:100,000epinephrine.