The aim of this study is to investigate the incidence of unplanned reoperations from all causes due to bleeding in neurosurgical patients. The medical records of patients who received neurosurgical procedures at our hospital were retrospectively reviewed and data of patients who received reoperations were extracted and summarized. A literature review was conducted of the Medline, Cochrane, EMBASE, and Google Scholar databases up to November 2013. The main outcome measure was the rate of unplanned reoperations due to bleeding. At our hospital, 68 patients with a mean age of 41.5 ± 21.5 years (range, 7 months to 76 years) received an unplanned reoperation. More than 70% of the patients were older than 18 years, 64.7% were males, and 94.1% had cranial surgery. Almost 60% of the patients received >1 blood transfusion (58.8%) after the first surgery. Of the 68 patients, 35 (51.5%) received a second operation due to bleeding. Univariate logistic regression analysis only showed that an increasing time interval between the first and second surgery was associated with a decreased chance of the reoperation being performed due to bleeding (odds ratio [OR] = 0.843, 95% confidence interval [CI]: 0.720-0.987; P = .033). Of 229 studies identified, 5 retrospective reports with a total of 1375 patients were included in the analysis. The rate of reoperations for bleeding in the 5 studies ranged from 4.2% to 31.5%. Employing measures to reduce postoperative bleeding may help reduce the rate of unplanned neurosurgical reoperations.