Proteases are among the key regulators of most forms of programmed cell death (PCD) in animals. Also in plants, many PCD processes have been associated with protease expression or activation. However, the functional evidence of the roles and actual modes of action of plant proteases in PCD remains surprisingly limited. In this review, we give an update on protease involvement in the context of developmentally regulated plant PCD. To illustrate the diversity of protease functions, we focus on several prominent developmental PCD processes, including xylem and tapetum maturation, suspensor elimination, endosperm degradation and seed coat formation, as well as plant senescence processes. Despite the substantial advance in the field, protease functions are still often only correlatively linked to developmental PCD, and the specific molecular roles of proteases in many developmental PCD processes remain to be elucidated.