In this dissertation different decision-making processes are considered. The concept of information is described and different types of information are identified. These are operative information, supportive information, state-of-the-art-information, feedback information, directive information and private-interpersonal information. The research method, which has been used in this investigation, is personal interviews. Those who participated in the investigation were decision-makers from five different organizations. One aim was to investigate decision-making processes used in organizations and compare them with certain theoretical decision-making processes. Another aim was to identify what types of information were used in the different parts of a decision-making process. One conclusion is that the decision-making processes used in organizations differ from each other, mostly in the first and last phase, but they are still fairly similar. The main difference in the first phase is the focus on the overall goal of the organization and in the last phase if evaluation is included in the decision-making process. Another conclusion is that all types of information, except private-interpersonal information, are used in the different decision-making processes.