Three major biological dressings are available for the temporary closure of wounds: partial-thickness cadaveric human allograft skin, several forms of partial-thickness antibiotic-treated porcine xenograft skin, and human amnion. Generally, biological dressings reduce pain, close the wound to contamination and fluid loss, and prepare the wound bed for permanent closure, usually with autografts. The three types of biological dressings differ in their performance, with allograft skin being clearly superior in its wound maintenance and preparation characteristics, while porcine xenograft presents serious difficulties in incorporation into the wound bed and antigenic challenge to the recipient, and amnion is excessively fragile and tends to allow wound desiccation. The most serious potential liability of biological wound dressings is transmission of infection; however, the actual incidence of such transmission is extremely low. The advantages of physiological coverage provided by biological wound dressings greatly outweighs the chance for harm in the case of human allograft.