Abstract Background This prospective randomized double-blind dose–response study aimed to determine the ED 50 and ED 95 of intrathecal levobupivacaine combined with morphine and sufentanil for elective Caesarean delivery. Methods Parturients undergoing elective Caesarean delivery were included and allocated to five levobupivacaine dose groups (6, 8, 10, 12, or 14 mg). Combined spinal–epidural (CSE) anaesthesia was performed, allowing intrathecal administration of the allocated dose of levobupivacaine with intrathecal morphine 100 µg and intrathecal sufentanil 2.5 µg, and insertion of epidural catheter for completing anaesthesia in the case of failure. The dose was considered as successful if a bilateral T6 sensory block to pinprick occurred in 15 min and if no epidural supplement was required during surgery. A probit regression analysis was perfomed to calculate the ED 50 and ED 95 of intrathecal levobupivacaine for Caesarean delivery. Results Eighty-five parturients were included. A block to T6 sensory level was reached in 15 min for most of the patients. The ED 50 and ED 95 of levobupivacaine were 6.2 mg (95% CI: 2.6–7.6) and 12.9 mg (11.1–17.9), respectively. Haemodynamic stability and the rate of nausea and vomiting were similar among groups. Greater doses of levobupivacaine were associated with increased motor block duration. Conclusions When combined with intrathecal sufentanil 2.5 µg and intrathecal morphine 100 µg, the ED 95 of intrathecal levobupivacaine is 12.9 mg for Caesarean delivery. If doses of levobupivacaine less than the ED 95 , particularly near the ED 50 , are used, these doses should be administered under a CSE technique.