Few studies have addressed the effects and adverse events associated with daily teriparatide use, as well as the adherence and causes for non-adherence, among Japanese patients with osteoporosis, particularly those older than 80 years. In this study, we aimed to clarify various parameters associated with daily teriparatide use in Japanese patients with osteoporosis in a real-world clinical setting. This retrospective study compared the persistence of daily teriparatide use and the associated effects and adverse events in older (≥80 years, n=52) and younger patients (<80 years, n=106) treated with teriparatide between May 2013 and May 2018 at a single orthopedic clinic. We observed a significantly higher treatment completion rate among younger patients compared to their older counterparts (59.6% vs. 40.6%, p=0.036). Of the 74 patients (both patient groups) who completed a 24-month treatment course, only one (1.35%) developed new vertebral fractures. Our findings suggest that older patients would benefit from consistent osteoporosis treatment, particularly with a generally safe and effective agent, such as teriparatide. However, Log-rank test also shows the older patients exhibits a greater tendency to drop out than the younger patients (p=0.0238). The older patients tended to continue to drop out from the beginning. Accordingly, our results emphasize the importance of interventions, especially continuous encouraging from the first self-injection of teriparatide.