Objective: Intrathecal morphine is used as an effective component of multimodal analgesia in postoperative analgesia in cesarean section patients. We aimed to analyze the relationship between intrathecal morphine administration and postdural puncture headache (PDPH), pain score and analgesia consumption in the postoperative period, and maternal fetal effects. Methods: One hundred four pregnant women aged ≥18 years (American Society of Anesthesiology physical status I or II, >36 weeks gestation) who were scheduled for elective cesarean section under spinal anaesthesia were included in this study. Spinal anesthesia consisted of bupivacaine with or without morphine (Group M: 10 mg heavy marcaine + 25 mcg fentanyl + 100 mcg morphine; Group F: 10 mg heavy marcaine + 25 mcg fentanyl). The effect of intrathecal morphine on PDPH, postoperative pain score, analgesia consumption, and maternal and fetal effects were recorded for 5 days. Results: PDPH developed in a total of 33 patients (Group M: 18 and Group F: 15, P=0.274). When we evaluated PDPH with the VAS, there was no significant difference between the groups. The postoperative visual analogue scale (VAS) was lower in the morphine group, and no statistically significant difference was found in the VAS 1st hr and VAS 2nd hr, whereas the VAS 6th hr and VAS 24th hr were found to be statistically significant. There was no difference in terms of PDPH, the first analgesic requirement and postoperative nausea-vomiting, but meperidine consumption was lower in the morphine group. Conclusion: Low-dose intrathecal morphine did not affect the incidence of PDPH. It is an effective method that can be used in cesarean section patients without increasing the maternal and fetal side effects from postoperative analgesia.