Porous anodic alumina (PAA) is a biomaterial based on a cost-effective electrochemical anodization of pure aluminum with unique geometrical properties, i.e., self-ordering hexagonal pore distribution, tunable pore diameters and interpore distances, and uniformity of the pores in the vertical direction (nanochannels). These remarkable properties have found important applications in several fields such as energy storage, optics, photonics, magnetism, catalysis and, in particular, in the biomedicine field. In this work, we review the current state of research and key issues on cell culture and implants, drug delivery systems with complex release profiles and specific action, and high efficiency and sensitivity biosensors with different biosensing mechanisms, all of them based on PAA. The biocompatibility, morphology of the surface, nanoestructural engineering in-depth, surface functionalization and coatings are discussed and analyzed in detail.