BACKGROUND Symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH) is a significant cause of delayed cerebral ischemia that leads to poor outcomes. Selective intra-arterial administration of fasudil hydrochloride (IAF) has been adopted for its vasodilatory effect on spasm arteries to prevent delayed cerebral ischemia. However, its effect on clinical outcomes and predictive factors for good recovery are not fully understood. This study aimed to investigate the outcomes of selective IAF and identify predictive factors for good outcomes in patients with cerebral vasospasm after SAH. METHODS A retrospective study of 36 patients with cerebral vasospasm following SAH who underwent selective IAF at our institution between January 2014 and May 2022 was conducted. We evaluated the improvements in neurological findings before and after selective IAF. Statistical analyses were performed to determine factors associated with good outcomes. RESULTS Selective IAF improved the neurological findings in 26 patients (72.2%). Pre-therapeutic absence of cerebral infarction in more than 1/3 of the spasm artery perfusion area was significantly associated with an improvement in neurological findings (p < 0.0001). Furthermore, there was a tendency for a good outcome when the age was younger (p = 0.093), and the spasm was limited to peripheral vessels (p = 0.065). CONCLUSIONS Our study indicates that selective IAF has a promising effect in improving symptomatic vasospasm, except when a large cerebral infarction exists in the spasm artery perfusion area. Early consideration of selective IAF could be recommended once patients experience symptomatic cerebral vasospasm after SAH.