Intracerebral hemorrhage (ICH) is associated with higher incidence of stroke-associated infection (SAI) as well as antibiotic use. However, there were few methods for judging proper antibiotic use in clinical manner. We introduce an index of antibiotic use, called personal antibiotic use density (PAUD), to evaluate the relation between antibiotic use and prognosis of ICH patients with SAI. A total of 162 in 570 ICH patients were observed to diagnose as SAI. Comparing with the survival patients, PAUD, ICH volume, National Institutes of Health Stroke Scale (NIHSS) score and ICH score were significantly higher among those who died, while the Glasgow Coma Scale score and the length of stay were significantly lower (P < 0.05). PAUD was identified as an independent risk factor of in-hospital death (OR 2.396, 95% CI 1.412-4.067, P = 0.001). In-hospital mortality was significantly lower in the low (P = 0.027) and intermediate PAUD (P < 0.001) groups than that in the high PAUD group. Cumulative in-hospital survival was significantly higher in low and intermediate PAUD groups (log rank test, P < 0.001). PAUD correlated positively with NIHSS score (r = 0.224, P < 0.001) and in-hospital mortality (r = 0.268, P = 0.001). The study indicated that PAUD is closely related to in-hospital prognosis of ICH patients with SAI. Higher PAUD may not be associated with better prognosis, but instead, higher risk of death.