A wound may be defined as an injury to any of the body's tissues, especially one caused by physical means and with interruption of continuity. Primary wound healing of a plan-to-plan oriented scar formation is usually accomplished by hand sewing or stapling the corresponding layers of each side of the incision. Both these methods have been associated to wound infection and granule formation due to their degradation in the organism. They also present other disadvantages, such as the need to be removed (in most cases) and the pain associated with their use. As a result of these shortcomings, surgeons have thought of an alternative way: the use of medical tissue adhesives. These adhesives consist on an attractive option to suturing or stapling since they can accomplish other tasks, such as haemostasis and the ability of sealing air leakages and also because they do not represent any risk of needlestick injury to medical staff. Also, the use of an adhesive would reduce the surgeries procedure time since its application presents itself as an easier and faster method to establish tissue adhesion. Despite their advantages, surgical adhesives must obey some clinical requirements. They must hold the two sides of the tissue together until it is no longer necessary, and then they should be degraded to biocompatible products. The most used surgical glues nowadays are the fibrin based adhesives and cyanoacrylates. Fibrin based adhesives present several problems, e.g. immunogenicity and risk of blood transmission diseases such as HIV and BSE. On the other hand, cyanoacrylates have been reported to degrade in aqueous media producing formaldehyde, which causes inflammation and has carcinogenic potential. Other options are now coming into light, and among the synthetic materials, urethane-based adhesives have been considered to be the most promising. These materials may be prepared under the form of pre-polymers (containing free isocyanate groups) and therefore being able to react with amino groups present in the biological molecules establishing adhesion. Another current area of research is the synthesis of UV-curable adhesives. These offer major advantages compared to pre-polymers systems, such as fastcuring rate, control of polymerization heat evolution and are ideal for application to weakened and diseased tissue. Throughout this chapter, examples of currently applied bioadhesives in surgery, as well as their advantages and disadvantages will be described. A special emphasis will be given to the development of polyurethane based adhesives both in the pre-polymer and UV-curable forms.