Obstructive uropathy due to ureteral stones can cause renal infection and, if left untreated, can cause impairment of renal function. Endoscopic surgery such as ureteroscopy (URS) and laser lithotripsy are the primary therapeutic approach. Cytokines as non invasive markers may have a role to diagnose ureteral damage and infection. We aimed to evaluate serum cytokine levels of tumor necrosis factor-a (TNFa) and interleukin-6 (IL6) in patients undergoing URS and holmium laser lithotripsy. The study included 40 patients (male 25 and 15 female) with a mean age of 47 years and 10 healthy blood donors serving as the control group. None of them had any additional systemic diseases, previous insertion of a ureteral double "j" stent or of a nephrostomy tube, neoplasmatic disease ot renal insufficiency. Routine urine examination and urine culture were obtained to exclude urinary infection. Preoperatively and 1h, 2h, 24h and 48h postoperatively serum samples of TNF-a and IL-6 were collected and measured. Serum TNFa and IL-6 values were correlated with the other variables measured from blood samples after the URS using paired samples Students t-test with confidence interval 95%. A P value of less than 0.01 was considered statistically significant. Correlation between serum TNF-a and IL6 levels with healthy donors were statistically significant in 1h (0.004), 2h (0.001), 24h (0.001) and 48h (0.001 and 0.001) postoperatively, respectively. In conclusion, our study shows that cytokines could be helpful as markers of renal tissue damage. However, further studies are needed to get more accurate results.