This article analyzes the attorney’s responsibility towards his client, in agreement with the obligations resulting from the power of attorney. It specifically refers to the lawyers who work as litigators, advisors, or consultants. The text begins with a study of the Law 1123 of 2007, which updates the attorneys’ disciplinary regulations, in order to highlight the references these regulations contain about the concept of suitability of the legal professional. It then explains the characteristics of the power of attorney between the lawyer and his client, as well as the main obligations—both of means and results—, and describes some specific cases in which the legal professional may fall in civil responsibility, as well as the forms and mechanisms of