With the advent of perforator-based skin transfer, computed tomography angiography has emerged as an invaluable tool in the preoperative planning of perforator flaps. But most likely, the exploitation of the technique is less than desirable. Through our experience with 144 patients, we evaluate the use of the free DICOM viewer OsiriX for Mac in the preoperative planning of perforator flaps with three objectives: 1) increase the present knowledge related with the preoperative planning of perforator flaps with computed tomography angiography, 2) evaluate the OsiriX application in the image post-processing of perforator flaps and 3) evaluate the performance of the procedure when performed by a surgeon (not specialized in Radiology). The experience has shown that the image post-processing performed by the surgeon with the OsiriX application usually allows an adequate evaluation of different structures and parameters of great preoperative interest in perforator flap surgery: 1) source artery, 2) diameter of artery and vein/s at the hypothetical site of microsurgical anastomoses, 3) course and branching pattern of the flap pedicle, 4) perforator course in the subcutaneous fat (theoretical flap axis), 5) measurement of the skin and fat where the perforator pierces the deep fascia (theoretical flap thickness ), 6) measurement of the distance between the point of entrance of the perforator in the subcutaneous fat to the source artery (theoretical maximal pedicle length) and 7) measurement of the perforator diameter where it pierces the deep fascia. Ultimately, in the authors' opinion, those plastic surgeons involved in perforator flap surgery would largely benefit from incorporating the image post-processing into their routine practice. The free DICOM viewer OsiriX is an efficient alternative, comparable to the more professional software only available in Radiology services. © 2013 Sociedad Española de Cirugía Plástica, Reparadora y Estética (SECPRE).