Nephrocalcinosis, the accumulation of calcium (Ca) in the kidneys, is associated with multiple renal disorders including renal stones. Populations with low risk of renal stones have been shown to have a diet high in fish oil, a rich source of omega-3 polyunsaturated fatty acids (n-3 PUFAs). However, sources of n-3 PUFAs differ in the amount, type, and structure. The study objective was to determine the effect of feeding different sources of n-3 PUFAs on the development of nephrocalcinosis. Young (age 28 day) female Sprague-Dawley rats were fed a casein diet supplemented with corn oil or omega-3 rich oils consisting of flaxseed, krill, menhaden, salmon, or tuna oil for 12 wks. Gas chromatography showed that renal fatty acid composition reflected the fatty acid profile of the dietary oils. RT-qPCR showed that rats fed fish oils had reduced inflammation as indicated by lower (P<0.05) COX-2 and TGF-β. Furthermore, rats fed salmon or tuna oil had increased (P<0.05) osteopontin (SPP1) gene expression, indicating antagonist action to renal Ca crystallization. Rats fed fish oils had lower (P<0.05) renal NFκB and prostaglandin E2 activity as determined by enzyme immunoassay. However, krill oil induced nephrocalcinosis due to the high phosphorous (P) content associated with phospholipids. Different sources of n-3 PUFAs mitigated the effects of nephrocalcinosis, but failed to prevent nephrocalcinosis due to Ca:P imbalance.