Vegetative propagation is a plant reproductive process in which somatic cells can form a new plant without undergoing sexual reproduction. Vegetative propagation in seed plants can be achieved by either somatic embryogenesis or de novo organ regeneration. Here we review the basic concepts and recent advances in research on de novo organ regeneration, which refers to the organogenesis of adventitious roots and/or shoots after injury has occurred. De novo organ regeneration can be observed under natural conditions and is also exploited in many agricultural techniques such as cuttings and tissue culture. The de novo organ regeneration process can occur in either a direct or an indirect manner. Cuttings are an example of direct de novo organ regeneration, during which adventitious roots directly regenerate from the wound site after detachment of the stem or leaf explant. Indirect de novo organ regeneration occurs in tissue culture, where a high auxin concentration induces detached explants to form a group of pluripotent cells known as callus, from which adventitious roots or shoots can be induced by a low concentration of auxin or a high concentration of cytokinin, respectively. The de novo organ regeneration process involves wound signals, hormone actions, transcription factors, and fate transition of stem cells. Understanding the cellular and molecular framework of de novo organ regeneration will improve the efficiency and success of vegetative propagation.