BACKGROUND: The prevalence of obesity is increasing at a disparaging rate in the United States. Although previous studies have associated obesity with increased surgical complications and readmission rates, the impact of obesity on surgical outcomes after cranial surgery remains understudied. The aim of this study is to assess the effect of obesity on complication and 30-day readmission rates after cranial surgery. METHODS: The medical records of 224 consecutive patients (nonobese, n = 164; obese, n = 60) undergoing either craniotomy or craniectomy at a major academic institution in 2011 were reviewed. Preoperative body mass index equal to or greater than 30 kg/m2 was classified as obese. The primary outcome investigated in this study was the rate of intraoperative and postoperative complications and 30-day readmissions after craniectomy/craniotomy. RESULTS: Baseline patient characteristics and comorbidities were similar between the cohorts. The mean body mass indexes for both cohorts were significantly different (nonobese, 22.8 ± 4.2 kg/m2 vs. obese, 45.1 ± 15.9 kg/m2; P < 0.0001). Most patients underwent tumor excision in both cohorts (nonobese, 64.0% vs. obese, 66.7%; P = 0.75). Compared with the nonobese cohort, the obese cohort had significantly higher estimated blood loss (nonobese, 209.9 ± 201.3 mL vs. obese, 284.9 ± 250.0 mL; P = 0.04), but similar length of operation (nonobese, 187.3 ± 89.4 minutes vs. obese, 209.6 ± 100.5; P = 0.14). Length of hospital stay and rate of postoperative complications were similar between both cohorts. Obese patients had increased rate of 30-day readmission, but this was not statistically significant (nonobese, 3.1% vs. obese, 6.7%; P = 0.25). CONCLUSIONS: Our study suggests that obesity may not have a significant impact on surgical outcomes after cranial surgery.