With 4D bioprinting, the creation of biological structures may incorporate time, a transformational factor, which is a substantial advancement above typical 3D printing. This development, which makes printed constructions capable of dynamically changing and responding to a variety of stimuli, including temperature, pH, and biochemical signals, has the potential to completely transform tissue engineering and regenerative medicine. Smart biomaterials, which may change their composition, structure, or function after creation to more accurately resemble the adaptive behaviors of real tissues, are at the heart of this breakthrough. This chapter explores the state of 4D bioprinting technology today and provides a thorough synopsis of the fundamental ideas in this area. Important ideas are carefully considered, such as the notion of 4D bioprinting and the mechanics of dynamic metamorphosis. Many kinds of smart biomaterials are discussed with their distinct characteristics, behaviors, and synthesis and characterization techniques. 4D bioprinting has several potential uses, including customized medicine, medication delivery, tissue engineering, and regenerative medicine. A comparison with 3D bioprinting is presented through case studies and recent research, highlighting noteworthy experiments and results that highlight the improved capabilities of 4D bioprinting. In addition to discussing potential issues and offering solutions, the chapter looks forward, spotting new developments and trends. Critical analysis is used to address ethical and regulatory issues, defining the frameworks and rules required to negotiate the complexity of this quickly developing technology.