The term “3D bioprinting”, which combines the words “3D printing” and “biology”, describes a cutting-edge method of advanced manufacturing, in which biomaterials or bioinks are deposited on strata ‘layer by layer’, as long as they are compatible with one another. It is used for various applications in the fields of tissue engineering, drug validation, pharmaceutical development, disease modeling, bioengineering, material science, and personalized medicine. The choice of biomaterials and the range of 3D-bioprinting technologies are linked to the final product's intended use. Some of the commercially available Cell-Printers are Fabion (3D-Bioprinting Solutions), Cell-Jet (Digilab), Rastrum (Inventia), and 3D-Bioplotter (Envision Tec). The goal of 3D-printed bioorgans is to address the lack of donor-organs to save lives and provide personalized treatment through the stacking of biomaterials, cells and biological components. The innovation faces several challenges, such as emulating the intricacy of real tissues, ensuring vascularization, biocompatibility, biofunctionality, regulatory approval/legal and ethical concerns, and the need to advance the technology. It is imperative to make advances in bioinks, multimaterial printing and biomimetic designs. Subsequent investigations will focus on improving printing accuracy, vascularization, and tissue integration. With the potential to revolutionize the fields of organ transplantation, disease modeling, drug testing, personalized medicine, and regenerative therapies, these technologies will ultimately enhance patient outcomes and quality of life. Some specific examples of 3D-bioorgans include 3D-printed skin, heart valve, ear, liver, kidney, cornea etc. To aid in the investigation of diabetes and develop efficient therapies, pancreatic tissues have been generated. These tissues have the ability to produce insulin and other hormones in a manner similar to that of the pancreas. In applications such as organ transplantation, medication testing, and disease modelling in healthcare and scientific research, 3D-printed organs are crucial. Improving patient outcomes and utilizing more individualized medical treatments is the ultimate goal. The technical challenges are the improved vascularization, accelerating the process to create full-sized organs, guaranteeing organ-functionality, and dealing with immunological reactions and biocompatibility. Higher costs associated with the development and production of 3D-printed organs limit the availability to the patients of low-income or underprivileged communities. Difficulty in maintenance of cell-environments, consumption of energy, regulatory approvals and ethical issues are some major concerns. Collaborative efforts with the pooling of interdisciplinary expertise are a pre-requisite. Advancements in printing technology, such as the creation of bioprinters with greater speed and resolution, and the incorporation of Artificial Intelligence and Machine-learning-Algorithms, will augment the success of their application potentials. Development of bioinks that can be adjusted to have mechanical and chemical characteristics similar to those of the extracellular matrix, use of new printer-tips, optimization of nozzle/needle-size, printing speed, layer-heights, pressure and temperature, creation of artificial and bio mimetic materials that can supplement/replace biological materials, promote immunomodulatory qualities and stringent ethical regulations are the efforts to enhance the success rate of this revolutionary technology in the field of medicine and allied disciplines. Majority of these requirements can be met with the advancements in additive manufacturing/3D-printing, with simultaneous advancements in engineering the cellular mechanisms that lead to tissue regeneration. In the field of fabricating biological organs, additive manufacturing or 3D-printing has become a game-changer. It brings with both, special opportunities and difficulties at the nexus of biology, engineering and medicine. This chapter offers a thorough examination of the meaning of bioorgans, the need for the disruptive technology of 3D-printing for the benefit of innumerable patients suffering from different organ abnormalities/disorders/failures, and the additive-manufacturing-techniques used in the production of bioorgans. The first section of the chapter provides a thorough introduction to the fundamentals of bioorgans, additive manufacturing procedures like stereolithography, extrusion-based printing, and inkjet-based printing, with a special focus on the identification and description of biomaterials that are appropriate for bio-organ printing, such as synthetic scaffolds, natural polymers, and hybrid materials with mechanical integrity, bioactivity, and built-in biocompatibility. The second section envisages creation and refinement of bio-inks, their interactions with cells, growth factors, and signaling molecules to promote tissue maturation, cellular differentiation, and proliferation in printed structures. Further, novelties in scaffold architecture are also discussed, including biomimetic architectures that facilitate functional integration and cellular organization, as well as hierarchical organization of biological structures and vascularization techniques. In addition, the chapter explores how bioprinting technologies, computational modeling, and imaging modalities work together to improve the functionality, accuracy, and repeatability of 3D-printed bioorgans. The translation of bio-organ-printing from bench to bedside involves a critical evaluation of regulatory considerations, ethical implications, and societal acceptance.