OBJECTIVE: We sought to examine whether the effect of treatment modality and drugs for cerebral vasospasm on clinical outcomes differs between elderly and non-elderly subarachnoid hemorrhage (SAH) patients in Japan. METHODS: We analyzed the J-ASPECT Study Diagnosis Procedure Combination database (n = 17,343) that underwent clipping or coiling between 2010 and 2014 in 579 hospitals. We stratified patients into two groups according to their age (elderly [≥75 years old], n = 3,885; non-elderly, n = 13,458). We analyzed the effect of treatment modality and anti-vasospasm agents (fasudil hydrochloride, ozagrel sodium, cilostazol, statin, eicosapentaenoic acid [EPA], and edaravone) on in-hospital poor outcomes (mRS 3-6 at discharge) and mortality using multivariable analysis. RESULTS: The elderly patients were more likely to be female, have impaired levels of consciousness and comorbidity, and less likely to be treated with clipping and anti-vasospasm agents, except for ozagrel sodium and statin. In-hospital mortality and poor outcomes were higher in the elderly (15.8% vs. 8.5%, 71.7% vs. 36.5%). Coiling was associated with higher mortality (odds ratio 1.43, 95% confidence interval 1.2-1.7) despite a lower proportion of poor outcomes (0.84, 0.75-0.94) in the non-elderly, in contrast to no effect on clinical outcomes in the elderly. A comparable effect of anti-vasospasm agents on mortality was observed between non-elderly and elderly for fasudil hydrochloride (non-elderly: 0.20, 0.17-0.24), statin (0.63, 0.50-0.79), ozagrel sodium (0.72, 0.60-0.86), and cilostazol (0.63, 0.51-0.77). Poor outcomes were inversely associated with fasudil hydrochloride (0.59, 0.51-0.68), statin (0.84, 0.75-0.94), and EPA (0.83, 0.72-0.94) use in the non-elderly. No effect of these agents on poor outcomes was observed in the elderly. CONCLUSIONS: In contrast to the non-elderly, no effect of treatment modality on clinical outcomes were observed in the elderly. A comparable effect of anti-vasospasm agents was observed on mortality, but not on functional outcomes, between the non-elderly and elderly.