Calcium oxalate monohydrate (COM) crystals are the commonest component of kidney stones. Oxalate and COM crystals in renal cells are thought to contribute to pathology via pro-oxidant events. Using an in vivo rat model of crystalluria induced by hyperoxaluria plus hypercalciuria (ethylene glycol [EG] plus 1, 25-dihydroxycholecalciferol [DHC]), we measured glutathione and energy homeostasis of kidney mitochondria. Hyperoxaluria or hypercalciuria without crystalluria were also investigated. After 1-3 weeks treatment, kidney cryosections were analysis by polarized and light microscopy. In kidney sub-cellular fractions glutathione and antioxidant enzymes were measured. In mitochondria oxygen consumption and superoxide formation as well as cytochrome c content were measured. EG plus DHC treatment increased formation of renal birefringent crystal. Histology revealed increased renal tubular pathology characterized by obstruction, distension, and interstitial inflammation. Crystalluria at all time points led to oxidative stress manifest as decreased cytosolic and mitochondrial glutathione, and increased activity of the antioxidant enzymes glutathione-reductase and -peroxidase (mitochondria), and glucose-6-phosphate dehydrogenase (cytosol). These changes were followed by a significant decrease in mitochondrial cytochrome c content at 2-3 weeks suggesting the involvement of apoptosis in the renal pathology. Mitochondrial oxygen consumption was severely impaired in the crystalluria group without increased mitochondrial superoxide formation. Some of these changes were also evident in hyperoxaluria at week 1, but were absent at later times and in all calciuric groups. Our data indicate that impaired electron flow did not cause superoxide formation however mitochondrial dysfunction contributes to pathological events when tubular crystal-cell interactions are uncontrolled, as in stones disease.