The paper explores various ways of business negotiation, business ethics, and whether all of that has impact on the game theory. Because of the extremely strong competition, business subjects are sometimes forced to go a step further, to the limits of ethical behavior. If they want to manage to increase their competitive advantage they often have to turn to various tactics that might exceed this limits, and starting to believe that what they do in fact is morally. Because companies want to increase their income and get as much of the marketplace as they can, in some situations it is important to cooperate with their competition. In any kind of negotiations all parties should have acces of the same information, but it rarely happens even though in some cases there would be a better result for all parties. In addition to problems in decision making and reaching an agreement that returns incomplete information, there is also the problem of different cultures. In different cultures, there is a misunderstanding in the negotiations due to insufficient knowledge of languages, beliefs and values of the different business subjects, which is why the party who is well prepared and knows all of this difference comes to advantages in bargaining, and achieves all its stated objectives. For all of these reasons there is game theory so they could on (not)honest way get as many pieces of the pie as they can.