Urolithiasis is one of the actual problems of the routine urological practice, given the high prevalence and high recurrence rates. In the urological clinics the patients with urolithiasis make up approximately 40% of the contingent. Majority of them are in the most productive age of 30-50 years old. Nearly 30% of the stones have infectious genesis, caused by the production of urease, changes in the urine pH, biofilm formation and followed by the precipitation of the salts. Bacterial colonies form the organic matrices, serving as the core for the stone formation and growth. Percutaneous nephrolithotripsy (PCNL) is a standard of care for staghorn stones with the clinical efficacy of 73-91%, nevertheless stone-free rate is not achievable in some cases. Despite the wide application of the high effective and non-invasive methods of the diagnostics and treatment of urolithiasis, the recurrence rate could be as high as 38.4%. The recurrence risk in patients with residual infectious stones is higher, than that in sterile calculi. Given that bacteria could stay long in the biofilms in the renal stones, they come out as a new core for the stone formation, which could be the most significant cause for recurrence. The destruction of stones during the PCNL could be a starting point for the activation of microorganism from the biofilms; their migration into the blood circulation and toxins could give a rise to infectious-inflammatory and septic complications. The biofilm rests on the pelvic mucosa and bacteriuria are the common risk factors for the stone recurrence postoperatively. This warrants the further search of the methods and medications to prevent the recurrence after PCNL.