The replies to a questionnaire about current microvascular practice circulated to microsurgeons worldwide are summarized and discussed. The material comprises results of 6,594 procedures performed during 1989. The survey topics dealt with include overall success rates in free flap transfer and replantation surgery, antithrombotic therapy, frequency of thrombosis, and frequency of reoperation. At centres not using antithrombotic therapy, the frequency of thrombosis in free flap procedures was higher than at centres using antithrombotic therapy, the result being a higher reoperation rate at the former. However, the final success rates for free flap transfers were about the same (95-96%). The success rate for replantation with antithrombotic therapy was 92%; few centres attempted replantation without such treatment, and at these centres, the success rate was 82%, and reoperation was not attempted. The same modes of antithrombotic therapy and postoperative monitoring are used worldwide.