The globalization of the economy has demanded that the companies implement technological platforms that support the new form to make businesses. The use of Internet for this aim, entails to that projects of computer science security are developed that guarantee integrity, availability and accessibility of the information. The creation of security policies is a fundamental work that it involves the people, the processes and the resources of the company. This I articulate presents/displays the key points to consider to design a security policy being based on norm ISO 17799.