The popularity of the sural artery flap has increased markedly throughout the years, and favorable results are reported almost uniformly. Previous publications have mainly presented results of small groups and of predominantly younger patients with posttraumatic defects, or they have reported technical modifications of the sural artery flap. The authors have increasingly used the reversed sural artery flap in a high-risk, critically multimorbid, and older patient population, and in contrast to the results of other authors, a considerable necrosis rate of 36 percent was seen. For the first time, a detailed, critical, retrospective complication analysis of 70 sural artery flaps is presented. The results reveal the following risk factors, which can potentially impair successful defect coverage and thus contribute to flap complications: concomitant diseases, particularly diabetes mellitus; peripheral arterial disease or venous insufficiency, which increase the risk of flap necrosis five-fold to six-fold; and patient age of over 40 years, because of an increased rate of comorbidity, underlying osteomyelitis, and the use of a tight subcutaneous tunnel. However, age alone did not seem to represent a risk factor by itself. Given the results of the analysis, the operative procedure was altered, as follows. In cases in which a lesser saphenous vein cannot be found, a delay procedure is recommended, or the flap is not utilized. In addition, an external fixation device seems to facilitate postoperative care markedly without adding specific complications; it is recommended in most patients. This analysis emphasizes specific risk factors that result in higher complication rates of the sural artery flap, and it leads to more realistic and appropriate expectations for this flap.