Shape-memory characteristics shed light on materials science and open horizons for accessing to unconventional functions in material categories subsuming metals, polymers, and ceramics. Biomedical fields manifest great interest in adopting shape-memory materials for unconventional properties, specifications, and well-defined mechanical properties. In spite of the mentioned advantages, their biocompatibility for long-term and permanent applications has not yet been comprehensively distinguished. This article summarizes the most common clinical applications of shape memory alloys and polymers, e.g., tissue engineering, drug delivery, hydrogels, orthodontic wires/distracters, artificial discs, orthopedic staples, atrial septal occlusion devices, neurosurgical stents, etc., and also addresses their critical biocompatibility issues.