In this paper we consider the idea of negotiations conducted by means of the software support tools. We present the advantages of the negotiation support systems discussing their different functions and typologies focusing later on the possibilities of decision support they can give to the negotiating parties in all negotiation phases. After presenting the most popular solutions we introduce also two of our own procedures that can be applied in the pre-negotiation phase for eliciting negotiators’ preferences and building the offers’ scoring systems for the parties. The first one is based on the Hammond, Keeney and Raiffa’s procedure of even swaps, while the second derives from the Roy’s ELECTRE-TRI. Both of them can be easily applied as the analytic engines in electronic negotiation systems replacing the classical additive scoring systems. We discuss also the issue of using different scoring systems in the successive negotiation phases.