Introduction: Controversy exists in antiepileptic drug (AED) prophylaxis prescribing in patients with aneurysmal subarachnoid hemorrhage (SAH). We undertook the Use of Antiepileptic Drugs in Aneurysmal Subarachnoid Hemorrhage (ALIBI) study to identify factors associated with prescribing practices. Methods: A retrospective chart review of all consecutive patients requiring Level 1 care with aneurysmal SAH admitted between 2012 and 2014 to the intensive care unit at Toronto Western Hospital, Ontario, Canada, was conducted. Data were collected on clinical and imaging characteristics. Primary and secondary outcomes were AED prophylaxis and clinical seizure activity during hospitalization. Data were compared using chi-square or Mann–Whitney U-tests. Those variables found to be significant, or trending toward significance, on univariate analysis were fitted to multivariate regression. Results: Sixty-eight patients were included. Mean age was 62 ± 12.2, and 42.6% of patients were male. Of these, 21 patients (30.9%) received AED prophylactically, while 18 (26.5%) had reported seizures at some point during hospitalization. Female gender and presence of midline shift (MLS) were significantly associated or approached significance with AED prophylaxis in univariate analysis (p = 0.036 and p = 0.062, respectively). In multivariate analysis, only MLS was an independent predictor (odds ratio 5.09, p = 0.04). Conclusion: The presence of MLS was an independent predictor of seizure activity in patients with aneurysmal SAH. AED prophylaxis prescribing patterns seemed arbitrary and was not informed by identifiable clinical factors or true risk factors for seizure. A current lack of evidence guiding AED prescribing practice highlights the need for larger studies in this patient population.