Free-tissue transfer has become an accepted method for reconstructing complex surgical defects. We review 25 years' experience of this approach. In France, microsurgery was first performed in 1974. I myself constructed 839 consecutive free flaps in 821 patients during a 25-year period. Here we distinguish between two different indications, namely malignant and benign lesions. In oncology, the patient recovers good quality of life even if the prognosis is poor. In contrast, the transplant offers permanent cure for patients with benign lesions. Microvascular anastomoses were constructed with separated stitches (90% of anastomoses); end-to-end anastomoses were preferred (85%). Manual suture with thread is the best technique. Post-operative flap monitoring included clinical observation, Doppler sonography, thermic probing, and endoscopy. The overall success rate of free flap reconstruction was 95.5%. In cancer patients, surviving flaps resulted in wound healing and did not delay post-operative irradiation or chemotherapy. The incidence of major complications (death 0.36%, necrosis 4.5%) and minor post operative complications (27.1%) was acceptable. The mean hospital stay was 20 days. Careful selection of the transplants yielded good reliability. Six donor sites were sufficient to reconstruct the majority of defects. Teaching of microsurgery is one of our main preoccupations. This is an indispensable technique in all fields of reconstruction. Rigorous training is necessary and much time must be spent before reaching a high level of reliability.