OBJECTIVE The purpose of this study was to determine predisposing factors for good clinical outcome in patients with spontaneous basal ganglia hemorrhage with borderline volumes (defined as a hematoma volume between 20 and 50 cm) who had undergone treatment by stereotactic catheter drainage. METHODS From the 298 patients whose information had been prospectively collected in the institutional database between January 2010 and December 2013, 93 patients were included in this retrospective study and divided into 2 groups: best medical treatment alone (Group A, n = 44) and best medical treatment plus catheterization (Group B, n = 49). All patients met the following criteria: 1) a diagnosis of spontaneous basal ganglia hemorrhage, and 2) a borderline hematoma volume (20 to 50 cm). Postoperative modified Rankin Scale (mRS) scores and recovery of motor weakness were compared between the 2 groups, and predisposing factors for good clinical outcome were evaluated. RESULTS Patients in Group B showed earlier recovery of motor weakness and improved mRS scores than patients in Group A. The final mRS score at 12 months was better in Group B than in Group A (p = 0.006). Predisposing factors for a good clinical outcome were a hematoma volume < 30 cm (OR 6.158, 95% CI 1.221-31.053, p = 0.028), an initial Glasgow Coma Scale (GCS) score ≥ 13 (OR 6.331, 95% CI 1.129-35.507, p = 0.036), the absence of internal capsule involvement (OR 4.680, 95% CI 1.152-19.010, p = 0.031), and catheterization (OR 13.376, 95% CI 2.423-73.842, p = 0.003) based on logistic regression analysis. CONCLUSIONS Good clinical outcome can be expected after stereotactic catheter drainage in patients with a hematoma volume between 20 and 30 cm, an initial GCS score ≥ 13, and the absence of internal capsule involvement. Among these patients, stereotactic catheter drainage may have a beneficial effect on early recovery of motor weakness and functional outcome, indicating that lateral-type basal ganglia hematoma compression not involving the internal capsule may be better treated using stereotactic catheter drainage than treated medically.