BACKGROUND: We aimed to investigate whether vaspin, a member of the serine protease family, could be used as a marker for the severity and prognosis of subarachnoid hemorrhage (SAH). METHODS: Fifty-Two consecutive patients (mean age, 51.46±3.2 years; 61.5% male) admitted to the emergency service of our hospital and hospitalized at our clinic with the diagnosis of aneurysmal SAH between 2012 and 2014 were included in the study and followed up for six months for outcome. The control group consisted of 52 healthy individuals of similar age and gender. RESULTS: During the 6-month follow-up, 8 of 52 patients died, and 18 (34.6%) patients had poor the Glasgow Outcome Score (GOS) scores. In 20 (38.46%) patients, acute hydrocephalus developed, and external ventricular drainage was performed. In the study group, the mean vaspin level was significantly higher than control group (157.88±33.6 pg/mL and 109.59±45.68 pg/mL, respectively; P<0.01). The mean vaspin level was 215.18±12.36 pg/mL in the non-survival group and 147.47±24.43 pg/mL in the survival group. Furthermore, it was 195.99±21.10 pg/mL in patients with poor outcome in terms of GOS, and 137.71±17.61 pg/mL in those with good outcome. The vaspin levels significantly increased with worsening of GOS, the World Federation of Neurological Surgeons (WFNS) grading system, and Fisher scores and increasing plasma Creactive protein levels (P<0.01 for all). CONCLUSIONS: In conclusion, vaspin can play a role as a new marker in the diagnosis, severity assessment, and prognosis of SAH.