"When analyzing the real estate market we should pay an attention to its actors. They are causative bodies, responsible for creating of the real estate system, who want to maximize their advantage or to satisfy their basic needs. In such an approach, real estateís agents, decide to participate in the real estate market taking under consideration their own needs, opportunities, expectations for market development and economic expertise - law. The decisions and actions they made are the outcome of rational premises. However, not all behaviors and processes can be classified as reasonable (and predictable). Market operators often active by an exclusion of participants awareness , in isolation from the economy, despite society expectations (needs). Such actions are called impulsive and they fit the behavioral trend of behavior taking place in the space of the real estate market. The article presents issues related to the rationality of the behavior of entities in the real estate market and their impulsive actions. Aim of this article is to show the duality of the behavior among real estate market participants. The practical part describes the behavior of participants in the property market by examining the ""certainty effect"", which is an integral part of prospect theory."