The aim of this study was to investigate the characteristics of postmenopausal women prescribed with teriparatide in Slovenia, during the first decade after its approval, and the predictors of bone mineral density (BMD) improvement with treatment. We retrospectively studied postmenopausal osteoporotic patients prescribed with teriparatide at tertiary center from 2006 to 2015. BMD was measured at standard sites by DXA at baseline, after 12 and 24 months. 25-hydroxyvitamin D and procollagen type I N-terminal propeptide (PINP) were measured at the same time-points. The inclusion criteria were met by 188 women (aged 71 years on average), 151 (80.3%) with postmenopausal and 37 (19.7%) with glucocorticoid-induced osteoporosis. Everyone had at least one fracture, 159 (84.6%) had ≥2 fractures, with vertebral fractures in 172 patients (91.5%). All patients had been previously on antiresorptives for 8.6 years on average. The average BMD change at lumbar spine, total hip, and femoral neck was +5.0%, −1.1%, and +0.3% after 24 months of treatment, respectively. Higher baseline PINP was associated with higher BMD increase at all sites after the first 12 months. Teriparatide was prescribed mostly to elderly women with severe osteoporosis who had sustained two or more fractures despite long-term antiresorptive therapy. Baseline PINP might predict initial BMD increase with teriparatide.