The potential of additive manufacturing to produce optimised and customized polymeric parts is often impaired by poor surface finish, low mechanical properties, and insufficient dimensional accuracy. Post-processing treatments are usually adopted to address these issues. Scientific community and industrial actors are engaged in the development and use of post-processing to enhance the performance and widen the range of application of polymeric components manufactured by additive technologies. The present work aims to provide an exhaustive classification and discussion of the post-processing treatments, as well as an extensive literature review of the approaches proposed within the scientific community. A holistic view of post-processing is provided, including a discussion of the benefits associated with each technique as well as its side effects. This work is intended to support the selection of the most appropriate post-processing by considering multiple aspects such as the material, part geometry, processing time, costs, and treatment specificity.