The effect and safety of endovascular treatment of basilar tip aneurysms associated with moyamoya disease are unknown. This study was to investigate the safety and effect of endovascular treatment of basilar tip aneurysms associated with moyamoya disease. Patients with moyamoya disease concurrent with basilar tip aneurysms were retrospectively enrolled and treated with endovascular embolization. The clinical and angiographic data were analyzed. Thirty patients with a basilar tip aneurysm were enrolled, including 8 (26.67%) male and 22 (73.33%) female patients aged 38 to 72 years (mean 54.4 ± 8.15). Endovascular treatment was successfully performed in 29 (96.67%) patients but failed in 1 (3.33%). Immediately after embolization, aneurysm occlusion degree was Raymond-Roy grade I in 26 (89.66%), grade II in 2 (6.90%), and grade III in 1 (3.45%). Intraprocedural complications occurred in 2 (10%) patients, including aneurysm rupture in 1 (3.33%), leading to death of the patient, and stent thrombosis in 2 (6.67%) which was successfully treated with thrombolysis. At discharge, good clinical outcome (modified Rankin Scale 0-2) was achieved in 29 (96.67%) and death in 1 (3.03%). Follow-up was performed 6 to 26 months (median 15) in 27 (93.1%) patients. Aneurysm occlusion degree was Raymond-Roy grade I in 21 (77.78%) patients, grade II in 4 (14.81%), and grade III in 2 (7.41%), not significantly (P = .67) different from those immediately after embolization. Aneurysm recurrence was found in 4 patients (14.81%). The clinical outcome was modified Rankin Scale 0 to 2 in all 27 patients, not significantly different from that at discharge. Endovascular embolization can be performed safely and effectively for basilar tip aneurysms associated with moyamoya disease even though more advanced embolization techniques are necessary.