Fibronectin (FN) solution purified from human blood plasma significantly increased the breaking strength of skin wounds in rats, when applied locally and/or intravenously. The best effect (more than 2-fold) was revealed after combined local and i. v. application of FN. Maximum stimulating activity was observed on the 3rd postoperative day, directly indicating the importance of FN for the early phases of wound healing. The data suggest the possibility of using FN preparations for the stimulation of tissue repair processes.