Abstract Disclosure: C.A. Muir: None. L.M. Raven: None. L. Goodall: None. J.R. Center: None. Background: Lung transplantation (LTx) is a life-saving treatment for end-stage pulmonary disease. With improvements in immunosuppression, LTx survival continues to improve with current 5-year survival rates of over 70%. Consequently, management of long-term transplant-related complications is increasingly important. Osteoporosis is one such complication, with the incidence of osteoporosis and osteoporotic fracture highest in LTx patients compared to other solid organ transplant recipients. Despite high fracture rates, including in patients treated with anti-resorptive medications, no data has been published using anabolic treatments for the management of osteoporosis in LTx recipients. Study design: Clinical case series. We present clinical, biochemical and bone mineral density data for four patients with severe osteoporosis post LTx treated with teriparatide. Results: Four LTx patients were treated with teriparatide 20 mcg daily for 18 months. Prednisone dose ranged between 5-10 mg daily throughout the treatment period. All patients had been previously treated for osteoporosis using zolendronate (last dose 12-24 months prior to teriparatide initiation). Bone turnover was monitored repeatedly during treatment in two patients. Following completion of teriparatide treatment, all patients received consolidation treatment with zolendronate (3 patients) or denosumab (1 patient). Bone density was measured prior and within 6-12 months after completion of teriparatide. All four patients experienced an increase in bone density at the spine (median 13%; range 2-14%) and total proximal femur (median 8%, range 6-10%) related to teriparatide treatment. No adverse effects were observed. Conclusion: Given that severe osteoporosis is highly prevalent in LTx patients and that fractures often continue to occur after treatment with anti-resorptive medication, teriparatide should be further studied as an alternative treatment in this clinical setting. Our experience in four patients suggest it is safe and effective. Presentation: Thursday, June 15, 2023