Uterine atony, or failure of the uterus to contract following delivery, is the most common cause of postpartum hemorrhage. This review serves to examine the prevention and treatment of uterine atony, including risk-factor recognition and active management of the third stage of labor. A range of uterotonic agents will be compared for efficacy, safety, and ease of administration. Oxytocin and ergot alkaloids represent the cornerstone of uterotonic therapy, while prostaglandin therapy has been studied more recently as an attractive alternative, particularly for resource-poor settings. Newer supplementary medical therapies, such as recombinant factor VII and hemostatic agents, and adjunctive nonsurgical methods aimed at achieving uterine tamponade will be evaluated.