Placenta previa accreta is a life-threatening obstetric condition that is responsible for massive obstetric hemorrhage that is a leading cause of pregnancy-related death. Interleukin-33 is associated with the invasion, proliferation, and metastasis of various cancers. The trophoblast of the placenta previa accreta invades into the myometrium in a similar way to the invasion of cancers. We studied the role of interleukine-33 in placenta previa accreta as a biomarker for antenatal diagnosis. To determine the usefulness of serum Interleukin-33 as a sensitive biomarker of invasive placentation. Prospective cohort study, in the department of Obstetrics and Gynecology at Al-Yarmouk-Teaching Hospital. This study included 90 cases of pregnant women divided into 3 groups, (group 1) 20 pregnant women diagnosed to have placenta previa accreta (group 2) 30 pregnant women diagnosed to have placenta previa nonadherent, and (control group3) which comprised of 40 pregnant women with the normal placenta. Serum samples were collected for both groups to measure Interleukin-33 levels by ELIZA method then statistical analysis was performed to detect the association between the interleukin-33 concentration and placental invasion. The result of the present study showed that serum interleukine-33 was significantly higher in placenta previa accreta patients when compared with placenta previa non-adherent and control group with a p-value = 0.001 and the interleukin-33 in cases who require urologist interventions and bladder repair was significantly higher p value=0.001and interleukine-33 level was also higher in cases which revealed percreta by histopathological reports than in cases of increta and accreta with p value=0.001. Higher levels of maternal serum IL-33 have been linked to placenta previa accreta, and greater levels in patients with percreta compared to increta and accreta show that IL-33 may play a role in aberrant placental invasion.