The osteocyte product sclerostin is emerging as an important paracrine regulator of bone mass. It has recently been shown that osteocyte production of receptor activator of NF-κB ligand (RANKL) is important in osteoclastic bone resorption, and we reported that exogenous treatment of osteocytes with sclerostin can increase RANKL-mediated osteoclast activity. There is good evidence that osteocytes can themselves liberate mineral from bone in a process known as osteocytic osteolysis. In the current study, we investigated sclerostin-stimulated mineral dissolution by human primary osteocyte-like cells (hOCy) and mouse MLO-Y4 cells. We found that sclerostin upregulated osteocyte expression of carbonic anhydrase 2 (CA2/Car2), cathepsin K (CTSK/Ctsk), and tartrate-resistant acid phosphatase (ACP5/Acp5). Because acidification of the extracellular matrix is a critical step in the release of mineral from bone, we further examined the regulation by sclerostin of CA2. Sclerostin stimulated CA2 mRNA and protein expression in hOCy and in MLO-Y4 cells. Sclerostin induced a decrease in intracellular pH (pHi) in both cell types as well as a decrease in extracellular pH (pHo) and the release of calcium ions from mineralized substrate. These effects were reversed in the co-presence of the carbonic anhydrase inhibitor, acetozolamide.