Introduction. Nephrolithiasis (urinary system stone disease) is one of the most common urological diseases. The estimated incidence of nephrolithiasis ranges from 2% to 3%. Approximately 19% of urinary system stone patients have insufficient fluid intake. Increasing the amount of daily drinking water leads to the increase in urine volume, which is inversely proportional to decrease in the incidence of urinary system stones. Aim of the Study: This study was planned to investigate dehydration, an indicator of water indispensable for our bodies, in patients who have been diagnosed with nephrolithiasis. Results: Clinical biochemical tests (creatinine, sodium, potassium, chlorine and calcium) and density, erythrocyte and leukocyte data of urine were obtained randomly and retrospectively from 60 patients and 60 healthy controls diagnosed with nephrolithiasis at the Meram Medical Faculty Hospital. Urinary densities Ratio in nephrolithiasis patients was found to be 1,017 ± 0,08 and 1,018 ± 0,023 in healthy controls. As a result of the analysis of variance using SPSS 22.0 program, there was no statistically significant difference between the two groups in terms of urinary density and other data (p> 0,05). Conclusions: Dehydration is known to be a risk factor for stone formation, and the normal urinary density of patients with nephrolithiasis in our study suggests that patients take into account the abundance of drinking water warnings after they have been diagnosed. Key words: Nephrolithiasis, etiology, dehydration