BACKGROUND Placenta accreta spectrum (PAS) disorders involve abnormal adhesion or invasion of chorionic villi through the myometrium and uterine serosa. Maternal anemia during pregnancy is common and may contribute to complications during delivery, particularly with abnormal placentation. This study examines the association between preoperative maternal hemoglobin levels and the risk of intraoperative massive hemorrhage in pregnant women with PAS disorders. MATERIAL AND METHODS A retrospective study included 538 consecutive participants (mean age=31.12±4.68 years) who underwent cesarean sections and met the diagnostic criteria for PAS disorders. Logistic regression analysis was performed to investigate the relationship between maternal preoperative hemoglobin levels and the risk of massive intraoperative hemorrhage (blood loss ≥1500 mL). RESULTS The incidence of intraoperative massive hemorrhage among patients with PAS disorders was 38.66%. The mean preoperative maternal hemoglobin level was 10.99±1.39 g/dL, and overall anemia incidence (<11 g/dL) was 48.88% in our study. After adjusting for potential confounders, a non-linear relationship was observed between preoperative maternal hemoglobin levels and the risk of intraoperative massive hemorrhage. When the preoperative hemoglobin level of pregnant women was below 11.5 g/dL (OR=0.52, 95% CI 0.39-0.70), the lower hemoglobin level significantly increased the risk of intraoperative hemorrhage. CONCLUSIONS Maternal preoperative hemoglobin levels were inversely associated with the risk of massive intraoperative hemorrhage in PAS disorders. A non-linear relationship was identified, with a turning point at 11.5 g/dL. These findings emphasize the importance of monitoring and managing maternal hemoglobin levels to mitigate the risk of intraoperative hemorrhage in pregnant women with PAS disorders.