The "Organs at risk" contouring workshop is a very helpful, interactive and practical way to learn more about contours of healthy tissues at risk of side effects from the radiation treatment. Very frequently we think we have the knowledge needed to draw volumes in radiation oncology, but once we are "hands-on" drawing these volumes, we have doubts/problems . This practical workshop helps to solve these doubts with the advice of very expert teachers. Another important aspect about this workshop, is that we usually spend hours studying how to draw the correct target volumes for tumors, but we do not study so much about how to delineate organs at risk. To achieve a good dosimetry, it´s essential to have appropriate volumes not only for tumor, but also for organs at risk to minimize toxicities from the treatment. This workshop will allow you to improve your contouring skills in a practical way, in an environment very similar to clinical practice, with basic and advanced delineation tools, fusion of different types of images, and which is very important, with the advice and teaching of some of the best experts in the field.