A fibrin wound dressing is made by mixing quantities of fibrinogen solution and thrombin solution with air. The resulting foam is very light weight, and with the proper attention to the amount of thrombin, will rest on a vertical surface without dripping. The wound dressing may also be formulated for its ability to continue migration of healing substances, such as PDGF, from the dressing to the wound site. Thrombin substitutes, such as other clotting proteins, may be used instead of thrombin. The resulting foam may also be lyophilized or ground and lyophilized for later reconstitution. A therapeutic drug or other additive may also be added to the wound dressing. A fibrin foam may be made by injecting fibrinogen foam into a clotting protein, such as thrombin.