Background: Caesarean delivery requires significant traction of peritoneum and intra-abdominal organs. Intra operative visceral pain is sometimes a problem during spinal anaesthesia. Increasing the dose of local anaesthestic is associated with less intra operative visceral pain. Objective: To evaluate the quality of intra operative analgesia and post-operative analgesia when fentanyl is added to intrathecal bupivacaine for caesarean section. Methods: Double blind, randomized controlled trial was conducted among 80 patients aged between 18-35 years from February 2007 to January 2008. 80 patients of the age group 18-35 years undergoing cesarean section, belonging to ASA Grade 1 were considered for this study. The patients were randomly divided into two groups of 40 patients each. Epi info 7 was used for analysis. Results: age and anthropometric characters (height and weight) were calculated in terms of mean and Standard deviation. As seen no significant difference was seen either in age, height or weight (p>0.05). For Mean BP at the time of arrival and during positioning for intrathecal injection: p > 0.05- not significant. After intrathecal injection: p < 0.01- highly significant. 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min after intrathecal injection: p > 0.05 – not significant. Conclusion: Addition of fentanyl (12.5 µg) to 0.5% hyperbaric Bupivacaine (10 mg) provides early onset of sensory blockade, improvement in intraoperative analgesia and significant increase in the duration of postoperative analgesia.