Introduction: It is considered that many factors may play a role in urolithiasis. Experimental and clinical studies have shown that zinc has an inhibitory effect on urolithiasis. Materials and Methods: In this study, urinary zinc and copper were measured in 27 healthy controls and 30 calcium oxalate stone formers. Results: Urinary zinc excretion was significantly higher (p < 0.001) in stone formers than healthy controls (2,575 ± 274 and 960 ± 80 mg/day, respectively). There was no significant difference in urinary copper excretion between healthy controls and stone formers (32.3 ± 3.5 and 33.3 ± 3.2 µg/day, respectively). Conclusions: According to our results, the potent inhibitory effect of urinary zinc excretion on urolithiasis could be reviewed.