Although the way of communicating with the customer has a great influence on the successful completion of the sales cycle, most people are not familiar with the mode of communication, which enables them to achieve their own goals, in a way that other people do not feel threatened or harmed. It is this way, ie the assertive way, that enables the seller to establish a good relationship with the buyer, respecting the buyer's problems or accepting suggestions. The notion of assertiveness means achieving one's own goals in a way that does not endanger the rights of others. Assertiveness is an alternative between an aggressive and passive way of communicating and behaving. Assertive behavior avoids all the physical and psychological consequences of aggressive and passive communication. Basically, there are four types of assertive behavior, basic assertiveness is characterized by the most basic confirmation of another participant's opinion, empathetic assertion, contains empathy. The use of escalating assertion may also give rise to certain forms of threat, which are permitted to end the conflict. Confrontative assertion is applied when the interlocutor needs to be warned to do what is not agreed. The realization that we are not invincible, the realization of our own shortcomings and boundaries, emotional intelligence, attending assertive training, influence the development of assertiveness. In communication with the buyer, the main task of the seller is to identify the motives for the purchase, and the best way to approach it. In the research part of the paper, conducted through a questionnaire among students of the Student dormitory in Pula, the aim was to examine the knowledge of the concept of assertiveness, where they got acquainted with the term, and how they react in situations when criticism should be received, to warn of bad actions, as well as to behave in conflict. The main conclusion of the research paper is that the respondents behave assertively, although they are not familiar with the concept of assertiveness.