The 2013 workshop of the Ercim working group on Multimedia Understanding through Semantics, Computation, and Learning (MUSCLE), was held in Antalya, Turkey, on October 3rd and 4th. The meeting was attended by 28 scientists, and featured 22 contributed presentations and three invited talks: “Medical Image Analysis: Visual Decomposition and Modeling”, by Prof. Metin Gurcan of Ohio State University, USA, “2D and 3D object registration without point correspondences”, by Prof. Zoltan Kato of University of Szeged, Hungary, and “Intelligent user interfaces: practical considerations in design and implementation,” by Prof. Metin Sezgin of Koc University, Istanbul, Turkey.