Purpose <p>Intraoperative pain is more common in emergency than elective caesarean sections (CS). This study aimed to determine the incidence, risk factors, and adverse maternal outcomes of intraoperative pain during non-elective CS under spinal anaesthesia.</p> Methods <p>In this prospective observational study, we enrolled parturients undergoing non-elective CS with spinal anaesthesia. Intraoperative pain was defined as complaints of pain or distressing sensations, including tugging, pressure or stabbing. Perioperative analgesia was standardised. The patients were followed up at 6&#xa0;weeks for postpartum depression (PPD) and at 3, 6 and 12&#xa0;months for chronic post-surgical pain (CPSP). The primary outcome was the incidence of intraoperative pain.</p> Results <p>425 patients were analysed for the primary outcome. The incidence of intraoperative pain was 5.88% (95% confidence interval [CI] 3.84% to 8.56%). Multivariable logistic regression identified the following risk factors for intraoperative pain: midline incision (odds ratio [OR] 5.71, 95% CI 1.009 to 29.70, <i>p</i> = 0.038), prolonged surgery duration (OR 1.10, 95% CI 1.01 to 1.19, per 1-min increase in surgery duration, <i>p</i> = 0.024) and a maximum sensory block height of T6 (OR 15.31, 95% CI 4.43 to 52.86, <i>p</i> &lt; 0.001). Patients who experienced intraoperative pain had higher acute postoperative pain scores, required more opioids, and increased incidences of PPD and CPSP compared to those without pain.</p> Conclusion <p>Intraoperative pain occurred in 5.88% of patients undergoing non-elective CS with spinal anaesthesia. Risk factors for intraoperative pain included midline incision, prolonged surgery, and a maximum sensory block height of T6. Intraoperative pain was associated with adverse short- and long-term maternal outcomes.</p>