Fluoride content was measured in 100 urinary stones retrieved by open surgery of stone formers admitted at PGIMS Rohtak and their respective urine and serum and compared with those of healthy individuals. The concentration of fluoride was also measured in the sources of drinking water of these stone formers. The concentration of fluoride was definitely significantly higher in serum (p>0.01) and highly significantly higher in urine (p>-0.001) of stone formers compared to those of healthy individuals. The content of oxalate in serum and 24 h urine of the stone formers was also measured, which was increased significantly (p<0.005 and p<0.001) compared to healthy individuals. The concentration of fluoride was probably significantly higher in drinking water of these stone formers than the normal ones. There was a positive correlation between the content of fluoride of urinary stones and urine of stone patients (r=.88); stone and serum (r=.62); drinking water and stone (r=.85) and their urine and serum (r=.54); urine and drinking water (r=.83) and serum and water (r=.51). These results indicate a definite role of fluoride in urinary stone formation.