Sub arachnoid blockade is the common form of centrineuraxial blockade performed for lower limb orthopaedic surgeries. The resulting nerve block using a local anesthetic agent ensures the patient well-being, while motor block facilitates the surgeon’s work. 0.5% hyperbaric bupivacaine is the most frequently used drug for SAB. After randomization patients were split into groups of 30 each by computer-generated random numbers, sealed in an envelop as slips folded in the OT complex. An independent observer picked up these slips and performed spinal or epidural anesthesia. Electrocardiogram (ECG), and a baseline reading of SpO2, heart rate (HR) and blood pressures, systolic (SBP) and diastolic (DBP) were recorded. This was an investigator and participant blinded study. The drugs that was given to the two different groups are as follows. Group A: Patients were administered with 15 mg bupivacaine 0.5% (H). Group B: Patients were administered with 7.5 mg bupivacaine 0.5% (H) + 25mcg fentanyl. Mean of Time for Sensory Regression to S1 is lesser in group B patients as compared to Group A and is statistically significant with p value of 0.0002. Mean of Time for Motor regression to Bromage 0 is lesser in group B patients as compared to Group A and is statistically significant with p value of < 0.001.