OBJECTIVES: Root canal treatment (RCT) is performed to get rid of pain resulting from the infection in the tooth. It is a safe procedure with high success rate. One of the main issues with root canal treatment is post-operative pain. There are many factors which can cause pain and distress to patients. If the clinician follows the guidelines properly and use the anxiety reduction protocol, then the procedure is not painful. RCT can be performed in multiple visits or it can be done in single visit. Present research was conducted to compare the single visit versus multiple visits endodontic treatment in teeth with pulpal necrosis in terms of post-operative pain frequency. METHODOLOGY: This study was a randomized controlled trial conducted at Department of Operative Dentistry, Fatima Memorial Hospital, Lahore, over a period of six months. Total number of participants was 302 and the teeth were lower and upper first and second molars with pulp necrosis and they were were equally assigned in two groups of 151with equal number of men and women. Single visit RCT was done in Group A patients, in which the endodontic procedure was performed in one day and multiple visit RCT was done in Group B, in which endodontic treatment was done in two or more visits. RESULTS: In necrosed teeth single visit endodontic treatment 20.5(%) resulted in less frequent post-operative pain than in multiple visit endodontic treatment (26.5%). CONCLUSION: Single visit endodontic treatment is a better technique in terms of pain control as compared to multiple visit in teeth with pulp necrosis. KEYWORDS: Endodontics, Non-vital teeth, Post-operative pain, single visit root canal treatment, multiple visit root canal treatment.