The aim of the study is: 1. To observe the onset time of sensory and motor blockade. 2. To compare levels and duration of sensory and motor blockade. 3. And to observe associated complications in subarachnoid block using 2.5 mL, 3 mL and 3.5 mL of 0.5% bupivacaine (hyperbaric). MATERIALS AND METHODS The prospective randomised clinical study was carried out on 90 patients belonging to ASA grade I and II, posted for elective urogenital, lower abdominal and lower extremities surgeries, under spinal anaesthesia. 90 patients were randomly divided into three groups using envelope method with 30 patients in each group. 1. Group A: Patients received 2.5 mL of hyperbaric solution of 0.5% bupivacaine. 2. Group B: Patients received 3.0 mL of hyperbaric solution of 0.5% bupivacaine. 3. Group C: Patients received 3.5 mL of hyperbaric solution of 0.5% bupivacaine. Immediately after the injection, the patient was positioned in the supine horizontal position and the following parameters were evaluated. Time of onset of sensory blockade, Maximum level of sensory blockade, Duration of sensory blockade, Time of onset of motor blockade, Maximum level of Motor blockade, Duration of motor blockade. RESULTS The onset of sensory and motor blockade was faster with the increasing volumes of the drug. Higher levels of sensory blockade were achieved with the increasing drug volumes. The duration of sensory and motor blockade increased with the increasing volumes of drug. The duration of motor block was directly proportional to the volume of the drug injected. CONCLUSION We conclude from our study that the doses of 0.5% hyperbaric bupivacaine can be titrated according to the level and duration of sensory and motor blockade desired using minimum amount of drug necessary. The cardiovascular stability was better at lower volumes of the drug.