General University Hospital Gregorio Maranon 1 article published in JoVE Medicine Combining Augmented Reality and 3D Printing to Display Patient Models on a Smartphone Rafael Moreta-Martinez1,2, David García-Mato1,2, Mónica García-Sevilla1,2, Rubén Pérez-Mañanes2,3,4, José A. Calvo-Haro2,3,4, Javier Pascau1,2 1Department of Bioengineering and Aerospace Engineering, Universidad Carlos III de Madrid, 2Instituto de Investigación Sanitaria Gregorio Marañón, 3Department of Orthopedic Surgery and Traumatology, Hospital General Universitario Gregorio Marañón, 4Department of Surgery, Faculty of Medicine, Universidad Complutense de Madrid Presented here is a method to design an augmented reality smartphone application for the visualization of anatomical three-dimensional models of patients using a 3D-printed reference marker.