In rabbits, a second-degree burn model with partial tangenitial excision of necrotic tissue was used to compare four dressing materials for effectiveness of promoting wound healing. The time of complete epithelization of the 2 X 4 cm large defect, changes in wound area, adherence of the dressings to the wound, and histology of the wound bed and dressings were measured. Dressings were changed twice weekly. Experiments showed that as a local dressing for burns, non-laminated collagen sponge was significantly better than pigskin or xeroform. Infection did not occur under it. It was very adherent to the burn wound and was actively permeated by inflammatory cells. This factor allowed early debridement of the wound. Effective debridement was probably responsible for the shorter healing time shown. Laminated collagen sponge was the poorest of the four dressings tested.