INTRODUCTION: Bupivacaine is commonly used in spinal anaesthesia for caesarean sometimes in combination with opioids. Most common adverse effect is significant incidence of hypotension. Maternal hypotension causes decreased placental perfusion which leads to adverse foetal outcome and may present with maternal vomiting, nausea and dizziness. Many spinal anaesthesia dosing regimen have been studied for caesarean section. While a fixed dose is preferred by some anaesthesiologists, others adjust the dose based on patient characteristics. Previous studies have confirmed that the final level of the block can be predicted by patient height and weight and would allow adequate segmental spinal spread with a decreased incidence of maternal hypotension. In some studies, local anaesthetic dose has been adjusted with height alone. However, whether level of the block is related to patient height and weight or height only is controversial. The purpose of this study was to determine the best dosing regimen with adequate anaesthesia and minimal side effects. MATERIALS AND METHODS: This was a randomized controlled study which was performed over a period of 18 months from September 2016 to march 2018 in Department of Anesthesiology, Krishna Institute of Medical Sciences University, Karad after approval of ethical committee of the institution.100 parturients posted for elective caesarean section after considering inclusion and exclusion criteria were divided into two groups (group I and II) of 50 each. Group I was given 0.5% hyperbaric bupivacaine, dose adjusted to height and weight and group II was given 0.5% hyperbaric bupivacaine, dose adjusted to height only. Time required to achieve adequate sensory block (T5), maximum level of sensory block and time required to attain maximum sensory block, total duration of sensory block, time required to attain complete motor block, total duration of motor block, and haemodynamic parameters including incidence of hypotension were noted. Other adverse effects like bradycardia, nausea and vomiting and neurological sequelae were recorded. RESULTS: The incidence of hypotension was more in height adjusted dose group (48% vs. 30%) but was not statistically significant. There was no significant difference in heart rate, SBP, DBP and MAP between two groups. The onset time for adequate sensory and motor block was longer in height adjusted dose group (4.44±0.99 minutes in group II vs. 4.18±1.7 minutes in group I and 2.21±0.45 in group II vs.2.10±0.5 in group I respectively) but was not statistically significant. In group I, 2% achieved maximum sensory block of T3, 32% attained T4 and 66% attained T5, while in group II, 2% attained maximum sensory block of T3, 38% attained T4 and 60% attained T5 .Time to attain maximum sensory block was more in height adjusted dose group (5.16±1.22 minutes vs. 4.86±1.49 minutes in group I) but was not statistically significant. The duration of sensory block at T5 and total duration of sensory block was more in weight and height adjusted dose group (64.39±17.65minutes in group I vs. 55.31±10.04 minutes in group II and 156.33±20.57 minutes in group I vs. 148.88±15.45 minutes in group II respectively) which was statistically significant. The total duration of motor block was more in weight and height adjusted dose group (127.96±19.69 minutes vs. 125.20±17.56 minutes in group II) but was not statistically significant. Incidence of bradycardia was more in height adjusted dose group (6% vs.2% in group I) and shivering was more in weight and height adjusted dose group (10% vs, 2% in group II) but was not statistically significant. CONCLUSION: Bupivacaine dose for spinal anaesthesia can be calculated based on height and weight or height alone. The study reveals that height and weight based dose can be superior.