Objective: Tiny intracranial aneurysms pose a great therapeutic challenge for endovascular embolization due to the difficulties in coil packing and risk of intraoperative aneurysm re-rupture. These aneurysms are defined as the maximum diameter of less than or equal to 3 mm. This study was designed to explore the clinical efficacy and prognosis of endovascular embolization in the treatment of ruptured tiny intracranial aneurysms. Method: A total of 46 patients with 46 ruptured tiny intracranial aneurysms admitted to our hospital were retrospectively analyzed and evaluated for clinical efficacy and follow-up results by the Modified Rankin Scale (MRS). Clinical efficacy was assessed by the embolization degree of aneurysms and perioperative complications. According to patients' MRS scores at 12 months after discharge, univariate analysis was performed for gender, age, hypertension, diabetes, smoking, Hunt-Hess grade (HHG), Modified Fisher Scale (MFS), time from admission to embolization, aneurysm location, embolization method, embolization degree and perioperative complications, and factors with statistically significant differences were included in multivariate logistic regression analysis. Results: There were 37 patients (80.4%) with complete embolization. Of the remaining 9 patients, 4 patients (8.7%) were found with sub-complete embolization and 5 patients (10.9%) with incomplete embolization. In the process of embolization, there were 4 cases (8.7%) of cerebral vasospasm, 3 cases (6.5%) of acute thrombosis and 3 cases of intraoperative aneurysm re-rupture. The postoperative complications included cerebral infarction in 2 cases (4.3%), serious hydrocephalus in 1 case (2.2%) and severe pulmonary infection in 1 case (2.2%). After treatment, the proportion of MRS score 0 and 1 was significantly higher than that at admission (P<0.05). During the follow-up of all patients for 12 months, 35 patients (76.1%) had good prognosis and 11 patients (23.9%) had poor prognosis. Univariate analysis showed that HHG, MFS and perioperative complications were the factors affecting the prognosis of patients (P<0.05), and were the independent risk factors affecting the prognosis of patients with ruptured tiny intracranial aneurysms (P<0.05). Conclusion: Endovascular embolization has been proven effective in the treatment of patients with ruptured tiny intracranial aneurysms. HHG, MFS and perioperative complications are significantly correlated to poor prognosis of patients, which is worthy of attention.