Until recently, the only therapeutic agents available for postmenopausal osteoporosis acted by inhibiting bone resorption and decreased the fracture risk by no more than 50%. Teriparatide, the recombinant 1-34 fragment of human parathyroid hormone, is a bone formation enhancer that has recently been licensed for use in established postmenopausal osteoporosis. Intermittent parathyroid hormone administration preferentially stimulates bone formation. The resultant increase in bone mass and improvement in bone architecture translate into a large decrease in the fracture risk that constitutes a major advance in the treatment of postmenopausal osteoporosis. Further work is needed to define the role for teriparatide in the therapeutic strategy for postmenopausal osteoporosis and to determine whether this agent is best used alone or in synchronous or sequential combination with bone resorption inhibitors.