In December of 2008, the Congress of the Republic of Colombia enacted a law (1258) creating a new form of hybrid-business entity referred to as the Simplified Stock Corporation (SAS). Following a liberalizing approach in corporate law, this act reduced all formalities for incorporation to a simple registration before a mercantile public registry. It also ameliorated expenses associated with the formation and operation of boards of directors, fiscal auditors, management structure and other formalistic requirements. This paper provides an analytical framework concerning the legal system of directors and officers provided for under Law 1258 of 2008 for the SAS. It focuses specifically on the duties applicable to managers and directors as well as the liabilities in which they may incur pursuant to the statutory provisions. Special attention is given also to the new regulation regarding shadow directors (managers de facto). According to this system, any person who is not a director or officer of the corporation, but interferes in its management or direction, shall incur in the same liabilities and penalties applicable to the latter. Such extrapolation of the legal regime applicable to directors and officers is intended to prevent third parties who intrude in the corporation’s affairs from avoiding the liabilities that normally arise for those who have management responsibilities in the corporation.