This study evaluated whether osteoporosis pharmacotherapy (OPT) affected functional outcomes in acute ischemic stroke patients with osteoporosis. Using a single-center registry database, we consecutively registered acute ischemic stroke patients between May 2016 and December 2020. All patients older than 55 years underwent routine bone densitometry within 7 days of stroke onset. OPT prescription was confirmed by reviewing medical records. We classified the patients into OPT and no OPT groups. We performed propensity score matching (PSM) to overcome the imbalance in multiple covariates between the two groups. We investigated whether OPT affected 1-year functional outcomes by multivariate analysis using a PSM cohort. Among 1307 consecutively registered acute ischemic stroke patients, 381 patients were enrolled in this study, of whom 134 (35.2%) were prescribed OPT at discharge, which was maintained for 1 year. In a multivariate analysis using a PSM cohort, the OPT group had a lower risk of dependency (odds ratio [OR], 0.52; 95% confidence interval [CI], 0.27–0.996) and poor functional outcome at 1 year (OR, 0.24; 95% CI, 0.10–0.57). The OPT group also had increased chance of late functional improvement (OR, 6.16; 95% CI, 1.12–33.79). This study showed that OPT could reduce dependency and poor functional outcomes and increase the chance of improving functional outcomes at 3 months and 1 year after ischemic stroke onset, and these findings could be helpful for improving functional outcomes and bone health after ischemic stroke.