The dilemma of the negotiator is a phenomenon that is derived from the tension that arises when, in the light of a specific situation, the optimum negotiation strategy must be discerned. The term was made popular by Professors David Lax and James Sebenius, of the Harvard Business School, to exemplify the dilemma between cooperating and competing in a negotiation. In this course, we first analyze the structure of the Dual Matrix that brings forth the five negotiation strategies, identifying the strengths and weaknesses of each, and the situations in which they work out best. We study the behaviours that lead to each strategy in order to reflect about our negotiation profile, which has historically driven us to use a preferential strategy, but which is not necessarily yielding the results expected. The participant will develop competences for strategic decision making, which will enable him to achieve the greatest benefit from a negotiation, in terms of creation of value and satisfaction between the parties involved.