Background Heart-type Fatty Acid-Binding Protein (H-FABP) and tau protein (τ) have been shown to be novel biomarkers associated with brain injury and, therefore, they could represent a useful diagnostic tool in patients with subarachnoid hemorrhage (SAH). The goal of this study was to measure H-FABP and τ in cerebrospinal fluid (CSF) following SAH to test the hypothesis that a relationship exists between SAH severity and H-FABP/τ values. Methods Twenty-seven consecutive SAH patients admitted to our ICU were studied. Serial CSF samples were obtained in every patient starting on the day of SAH and daily for up to 2 weeks post-SAH. H-FABP/τ levels were measured by enzyme-linked immunosorbent assay. Results Patients with severe SAH showed significantly higher peak levels of H-FABP and τ compared to mild-SAH patients (FABP: p=0.02; τ: p=0.002). In addition the peak concentrations of H-FABP and τ in CSF from SAH patients correlated significantly with Glasgow Coma Scale motor score (H-FABP: Spearman r=-0.52, p=0.006; τ: Spearman r=-0.63, p=0.0004). Based on outcome at discharge from the hospital, patients were categorized into survivors and non-survivors. Peak concentrations of both proteins in the non-survivors group were significantly higher than in the survivors. Conclusions H-FABP and τ CSF levels are proportional to SAH severity and may be novel biomarkers that can be used to predict the severity of outcome following clinical SAH.