In seed plants, the egg and the other six cells in the female gametophyte, are located in the ovule. After fertilization, the central cell forms the triploid endosperm, the zygote develops into the embryo and the maternal integuments nurture the embryo and develop into the testa or seed coat; at maturity these three components form a seed. Ovule abortion is of critical importance in shaping reproductive outcomes, leading to the high fitness of maternal offspring. The hypothesis that seed formation is solely limited by available resources has been refuted; plant ovules and embryos play key roles in maximizing reproductive success. Recent advancements have been made in understanding the mechanisms that derail the development of ovules into viable seeds. Hormonal signaling, stress responses, maternal regulation, and nutrient partitioning are all integrated during seed development. Work on the underlying mechanisms governing ovule abortion, considering factors such as genetic regulation, environmental influences, and the interplay of signaling pathways, is reviewed. By examining instances of ovule abortion in plants, the ecological implications and adaptive significance of this phenomenon are explored.