Model-Based Definition (MBD), as a paradigm for achieving more effective data and expert knowledge transfer of a 3D product and manufacturing information (PMI), is based on a 3D model with integrated information, such as geometric tolerances, surface finish, welding, material, bill of materials and other. Geometric dimensioning and tolerancing (GD&T) integration within MBD is based on the new ASME and ISO standards and it is represented in 3D models. Coupling between geometric tolerancing and MBD for parts and assemblies is evolving continually, thus becoming an effective learning, validation and representation tool for engineers in the product design phase, as well as in production and inspection planning. In this paper, a concurrent approach to learning GD&T and MBD is presented and the challenges and advantages are discussed. Examples and case studies of assemblies and parts are used for better understanding of the purpose of geometric tolerances, thus making the problems less abstract for the students. 3D visualization of tolerance features, feature groups, basic dimensions, standard related rules, and automatic assignment and validation tools, together with MBD training, theoretic and practical instructions, sketches, computations and explanations, are used to support the learning process of GD&T.