Background: Intracranial Atherosclerotic Disease (ICAD) large vessel occlusion (LVO) is responsible for up to 30% of anterior circulation LVOs and is less amenable to mechanical thrombectomy. In this study we aim to determine the prevalence of ICAD acute basilar occlusion and the likelihood of favorable functional outcomes (mRS 0-3) compared to embolic basilar occlusion. Methods: This is an analysis of PC-SEARCH Thrombectomy Registry in which consecutive patients with acute basilar artery occlusions from 8 high-volume comprehensive stroke centers were included from January 2015 to December 2021. Patients were dichotomized into two cohorts: with or without underlying ICAD. Descriptive statistics for each group and multivariate logistic analysis was performed on the primary outcome. Results: Three-hundred-ninety-nine patients were included in this analysis. There were 143 (36%) and 256 (64%) patients with and without ICAD; respectively. Baseline demographics were equivalent between the two groups except for gender (male 67% vs 47%; p < 0.001), history of stroke (24% vs 14%; p = 0.01), and atrial fibrillation (18% vs 30%; p = 0.01). Presenting NIHSS was similar between groups (15 vs 16; p = 0.85), however, pc-ASPECTS was higher in the ICAD group (9 vs 8; p = 0.02). At 90 days, patients with ICAD were less likely to achieve favorable functional outcomes (OR 0.33 95% CI 0.18 - 0.59; p < 0.001) after adjusting for potential confounding factors. Additionally, ICAD patients were less likely to achieve TICI ≥2b (38% vs 49%; p < 0.001). There were equivalent rates of symptomatic ICH between groups (OR 0.8 95% CI 0.29 - 2.22; p = 0.66). Conclusion: Acute basilar artery occlusions with underlying ICAD have higher likelihood of morbidity and mortality. Lower rates of successful recanalization in the ICAD cohort support this finding; however, rates of sICH were similar between the two cohorts.