Diffuse osteopenia is not generally recognized as a radiological manifestation of skeletal sarcoidosis. Furthermore, the pathologic correlates of the skeletal abnormalities in sarcoidosis are poorly characterized. We quantitated the histomorphometric parameters of bone formation and resorption in a transiliac crest biopsy specimen from a patient with sarcoidosis, diffuse osteopenia, hypercalcemia, and hypercalciuria, who was treated only intermittently with corticosteroids and thiazides. Peritrabecular granulomas were associated with the histologic features of accelerated bone remodeling, namely: excess osteoid; increased numbers of osteoclasts and osteoblasts; increased osteoclastic resorbing surfaces; and increased bone formation rate. We conclude that the peritrabecular granulomas of skeletal sarcoidosis may result in rapid bone turnover with diffuse osteopenia which may contribute to the abnormalities of mineral metabolism.