Prophylactic low-dose aspirin reduces the rates of preeclampsia, preterm birth, fetal growth restriction, and perinatal death in patients with risk factors for preeclampsia. Despite recommendations from the US Preventive Services Task Force, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine, low-dose aspirin use is reported in <50% of patients with high-risk factors and <25% of patients with >1 moderate-risk factor. These low use rates represent an important “quality gap” and demonstrate the need for quality improvement activities. In this article, we outline the specifications for a process metric to standardize the measurement of the rate of aspirin use. Furthermore, we outline an approach to conducting a quality improvement project to increase the use of aspirin by patients with risk factors for preeclampsia.