Background: Intra-arterial nimodipine (IAN) injections are performed in refractory delayed cerebral ischemia (DCI) related to cerebral vasospasm (CVS) after spontaneous subarachnoid hemorrhage (sSAH), but the clinical benefits are inconclusive and angiographic treatment failure is observed. We analyzed angiographic IAN response in a detailed vessel-specific manner and examined the impact of poor angiographic response on the further clinical course. Methods: Clinical data were retrospectively assessed in patients with spontaneous subarachnoid hemorrhage with symptomatic CVS receiving IAN bolus treatment. Clinical and angiographic predictors for poor angiographic response, DCI-related infarction, and unfavorable outcome were analyzed. Results: Eighty-nine patients were included and 356 treated vessel segments, mainly located in the anterior circulation (93%), were analyzed. Angiographic response was good in 77% of the treated segments. Older age, poor World Federation of Neurosurgical Societies (WFNS) grade 4–5 and early onset of CVS were independently associated with poor angiographic response. The factors short-segment, distal, and bilateral CVS as well as treatment of multiple vessel segments, WFNS grade 4–5, and early onset of CVS were significantly associated with an increased risk of DCI-related infarction. Clinical outcome was significantly influenced by poor WFNS grade and early onset of CVS, whereas poor angiographic response was not related to DCI-related infarction or unfavorable outcome. Conclusions: The risk of angiographic treatment failure is significantly increased in older patients and those with poor WFNS grade as in cases of early-onset CVS. Although the extent of angiographic CVS significantly affected the development of DCI-related infarction, poor angiographic response had no impact on cerebral infarction and clinical outcome.