assumption is neither correct. One of the reasons why projects fail in spite of project management is that there are various myths which make managers believe they are doing well their work, but with a critical analysis they would realize that they can improve it. This piece of work analyzes the most common myths within the project environment. Most of these myths can be identified as manage-ment mistakes caused by superficial knowledge and subjective assump-tions without scientific evidence. But why there are so many myths? Why do not project managers realize the mistakes they make? On the one hand project management is a young discipline in the economy. The first project management tools were developed in the 1950s. Therefore companies do mistakes because of missing preferences (Maylor, 2003, p.6-7). But one the other hand managers make not realize mistakes because of coincidences. If a project succeeds because the worst case did not come along, the executive manager often thinks that he did all right and he is going to plan another project in the same way with the same mistakes. With the right techniques and risk management one can decrease the possibility that a project fails a lot. Nevertheless they do not know if they will have success but they can minimize risks in avoiding common myths which are analyzed by this piece of work.