External ventricular drainage (EVD) is the routine intraventricular hemorrhage (IVH) treatment. Neurological deterioration and symptomatic hydrocephalus are often the default indications for EVD insertion. However, the outcome of preventive EVD is unclear in patients with mild IVH. This study aimed to determine whether EVD is beneficial in patients with mild IVH. This study aimed to determine whether EVD is beneficial in patients with mild IVH. Data from IVH patients treated conservatively or with EVD at two hospitals from January 2017 to December 2022 were analyzed retrospectively. Patients with a Glasgow Coma Scale (GCS) score of 12-14 and a modified Graeb score (mGS) >= 5 at admission were included. The primary outcome was poor functional status, defined as a modified Rankin Scale (mRS) score of 3-6 at 90 days. Secondary outcomes included the distribution of mRS score categories, the resolution time of intraventricular blood clots, and complications. Forty-nine patients were enrolled in the study: 21 patients in the EVD group, 28 in the non-EVD group, and 13 in the EVD group who received urokinase injections. ICH volume was an independent predictor of poor functional status. Currently, no evidence supports that preventive EVD benefits patients with mild IVH.