Objective: This study aimed to evaluate the regular medications prescribed to elderly neurosurgical inpatients in community hospitals in Japan.Materials and Methods: Elderly patients (aged ≥ 65 years) who had been admitted to neurosurgery departments from April 2015 to March 2017 were enrolled in this study. We collected data on regular medications at the time of admission and discharge. Furthermore, we retrospectively analyzed factors associated with potentially inappropriate medications (PIMs). PIMs were defined as polypharmacy (≥ 6 medications used concurrently) or taking any of the unfavorable medications on the “list of drugs to be prescribed with special caution” in the “Guidelines for Medical Treatment and Its Safety in the Elderly 2015”.Results: We gathered data on over 1900 medications (mean number, 5.04) prescribed to 197 patients (mean age, 76.9 years). PIMs were observed in 51.3% of patients on admission. The most common prescriptions resulting in PIMs were benzodiazepine agents, followed by loop diuretics and H2 receptor antagonists. The multivariate analysis revealed that age (odds ratio, 1.08; p < 0.01) and the number of prescribers (odds ratio, 6.16; p < 0.01) were significantly related to PIMs on admission. PIM exposure at the time of discharge accounted for 39.1%, a 12.2% decrease.Conclusion: More than half of the elderly patients were prescribed PIMs on admission; however, this exposure decreased by 12.2% at the time of discharge. Hospitalization is an optimal opportunity for reconsidering the necessity of medications and for changing the prescriptions according to patients’ conditions.