The lysosomal acid exo-hydrolase, β-glucuronidase (βGUS), catalyses the breakdown of multiple glycosaminoglycan chains. Loss of βGUS activity results in the lysosomal accumulation of glycosaminoglycans and the inherited metabolic disorder mucopolysaccharidosis type VII (MPS VII). Affected children display multiple organ abnormalities including severe and progressive skeletal dysplasia. Using the MPS VII mouse model we have shown that bone mineral volume and trabecular number increase in MPS VII, along with a decrease in both total osteoclast number and the number of osteoclasts attached to bone surface. In vitro, the addition of M-CSF and RANK-L to the culture medium of spleen monocytes isolated from βGUS mice supported normal levels of osteoclast formation. However, the derived osteoclasts had a reduced ability to form resorption pits compared to normal, with a reduction of approximately 22%. The expression of Rab7 and V-ATPase, mediators of vesicle fusion and transport were reduced, while actin ring formation was also impaired in MPS VII osteoclasts. In addition, MPS VII osteoblasts were less able to support osteoclastogenesis than normal mouse osteoblasts and produced significantly more OPG than normal. The loss of βGUS activity thus affects osteoclast activity directly through a re-oragnisation of the cytoskeleton and a downregulation of mediators and components crucial for vesicle fusion and trafficking along microtubules. Loss of βGUS activity also indirectly affects osteoclast formation by suppressing osteoblast function. Collectively, these results indicate the importance of βGUS for osteoclast function and normal bone remodeling.