The purpose of two described experiments was to examine whether emotional intelligence influences the style, dynamics, and effectiveness of business negotiations. Based on a theoretical model that defines emotional intelligence as a set of skills and abilities, it was expected that emotionally intelligent individuals would utilize their own emotions as well as knowledge on their opponent’s emotional states, which would affect their negotiation style and enhance its efficiency. The results of the two experiments (n = 127 and n = 103) revealed that emotionally intelligent negotiators put forward high initial offers, are not easily inclined to make concessions, and achieve higher final values as compared to individuals with lower emotional intelligence. The studies have proved that the level of emotional intelligence does not directly translate into any particular negotiation style; however, it is significantly linked to the ability to adjust the style as soon as the opponent’s emotions become apparent.