The choice between thoracodorsal and internal thoracic as recipient vessels for breast reconstruction have been discussed by several authors. Anatomical studies revealed little differences between these pedicles, however the presence of degenerative changes may lead to flap failure and might be a significant difference between them. Fifty-four vessels of bilateral thoracodorsal, internal thoracic and deep inferior epigastric pedicles were dissected on 9 fresh cadavers. Samples of perforator vessels with 1.5 cm long were harvested and fixed with formalin. Five millimeters sections of paraffin-embedded tissue were stained with hematoxilin-eosin, Verhoeff and Picrosirius. Histological degenerative changes were evaluated and histomorphometric measurements were made. Data were analyzed with a computer assisted device with OptimasŪ software. Major arterial degenerative changes were found in 7 thoracodorsal (38,9 %), 3 internal thoracic (16,7 %) and 2 deep inferior epigastric (11,1 %) vessels. The mean external diameter was 1.25, 1.82 and 1.67 mm respectively. There was one case of chronic arterial thrombosis with signs of reperfusion. Although a more similar diameter between deep inferior epigastric and internal thoracic arteries were found, in clinical practice the technical difficulties of vascular anastomosis with the thoracodorsal pedicle are the same. The higher number of degenerative changes observed in thoracodorsal vessels may be related to a higher number of thrombosis and flap failure. The authors believe that a careful patient selection is required to avoid further complications. Comparative clinical studies must be done to elucidate the real importance of such findings.