Due to the growing number of cesarean deliveries, the frequency of abnormally invasive placentation is increasing. The optimal management of this condition remains unclear. This article reviews the efficacy and safety of conservative management of abnormally invasive placentation. We performed a MEDLINE and Embase search and reviewed all articles on conservative management of abnormally invasive placentation published from 1985 through 2006. Over the past 20 years, 48 reports have described outcomes of 60 women who were treated conservatively for abnormally invasive placentation. Twenty-six women were managed without any additional interventions. In most of these patients (19/26), the placenta had been partially removed. In 4 of these 26, conservative therapy failed. Twenty-two women received adjuvant methotrexate. In most of these women (19/22), the entire placenta was left in situ. In 5, therapy failed. Twelve women were managed with arterial embolization. In most of these (9/12), the diagnosis was made antepartum and the placenta was completely left in situ. In 3, therapy failed. Overall, 11 women experienced infection (11/60), 21 women experienced vaginal bleeding (21/60), and 4 suffered disseminated intravascular coagulopathy (4/60). Spontaneous loss of placental tissue was noted in 16 women. Subsequent pregnancies were reported in 8 women. Conservative management of abnormally invasive placentation can be effective and fertility can be preserved. It should only be considered in highly selected cases when blood loss is minimal and there is desire for fertility preservation. Whether adjuvant methotrexate or selective arterial embolization is beneficial is uncertain. Undetectable hCG values do not seem to guarantee complete resorption of retained placental tissue. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians LEARNING OBJECTIVES: After completion of this article, the reader should be able to explain that there are methods to successfully treat abnormal placentation with conservative means, but these methods must be applied only in highly selected cases and recall that no one method is superior to the other.