Aim: Pain associated with Propofol injection is quite distressing. This study was aimed to compare the effectivness of ondensetron and fentanyl for alleviation of pain caused by propofol injection. Setting and design: Prospective comparative observational study. Methods and Material: A prospective observational study was conducted on 90 patients who were scheduled for the elective surgeries under general anaesthesia and received inj.propofol as an induction agent. Patients who received pretreatment with ondensetron (4 mg) before Propofol injection formed group O (n=30) while patients who received fentanyl (100 µg) as a pretreatment or nothing formed group F (n=30) and group P (n=30) respectively. The primary outcome recorded was the incidence of pain after propofol injection. We also assessed severity of pain and local reaction at the site of injection. Statistical analysis used: Purposive sampling method used for calculation of sample size. Data were analysed using SPSS softwere version 16.0. ANOVA test were used to compare quantitative data while chi-square test and fisher’s exact test were used to compare qualitative data. p value <0.05 was considered as a significant. Results: The incidence of pain was significantly low in group O (13.3%) and group F (13.3%) compared to group P (100%). Among all the patients who had pain, patients of group O and group F experienced only mild pain while patients of group P experienced moderate to severe pain. None of the patient had inflammatory reaction at local site. Conclusion: Pretreatment with Ondensetron or Fentanyl is equally effective for alleviation of pain caused by Propofol injection.