The objective of this thesis is to answer the following research question: what are the limits to the validity of contracts on human tissue in the Italian, English and EU legal system? In order to establish such limits, this study focuses on the following possible cases of contractual relations for the transfer and use of human tissue: a) Gratuitous contracts between the first transferor and the first recipient of human tissue; b) Non-gratuitous contracts between the first transferor and the first recipient; c) Contracts between the first and subsequent recipients. The research concludes that it is desirable to regulate, via contract law legislative provisions, the tissue transfers for the purposes of research. This regulation should place on the first recipient a clear set of information duties towards the first transferor of the tissue. In addition, such regulation should include mandatory and default rules for contracts between the first transferor and first recipient. The interaction between mandatory norms and default rules could achieve a strengthened protection of the autonomy of the first transferor of tissue. This research also demonstrates that the conclusion of sales and other non-gratuitous contracts on human tissue between first transferor and the first recipient should not be prohibited.