Postpartum hemorrhage is a leading cause of maternal mortality. Various methods can be used to evaluate the postpartum uterine cavity volume. This work aims to introduce a simple method for uterine postpartum cavity volume evaluation, called Postpartum Uterine Ultrasonographic Scale (PUUS), which could be used routinely. In this prospective study, 131 consecutive Caucasian patients were evaluated by using the PUUS method. The mean age was 27.72 years (ranging from 15 to 42). Patients were examined in the same time intervals: within the first 24-48 hours after delivery in case of vaginal delivery, and within the first 48-72 hours, in case of cesarean delivery. Patients with PUUS grades 2, 3, or 4 were reexamined daily until the PUUS grade declined to 1 or 0. The PUUS method evaluated the length of the endometrium of the uterine cavity occupied by blood or debris, from grade 0 (no blood) to grade 4 (over three-quarters of the endometrial length occupied by blood/debris). The PUUS grade of uterine involution varied with the day of examination, gestation, and parity. In this article, a novel method of evaluating uterine postpartum involution titled PUUS is introduced. This method standardized uterine cavity involution in a numerical fashion. We hope that the PUUS scale could further be used to decrease the morbidity and mortality of women due to postpartum hemorrhage.