At present time true reasons of calculi formation in kidneys and salivary glands are unknown. Pathogenic calculi formation in these organs could be consequences for example of mineral and ferment metabolism failures or influence of different external factors. The purpose of this investigation: to study of the frequency and combinations of urolithiasis and sialic lithiasis and compare of the mineral composition of sialic and renal calculi. 84 patients with sialic lithiasis and 50 patients with urolithiasis were examined. X-ray phase analysis and infrared spectroscopy were used for determination of mineral composition and structure of sialic and renal calculi. Study of salivary and urinary stones showed that all studied sialoliths similar in structure phosphate urinary stones. When comparing the IR spectrograms uroliths revealed their characteristic spectral bands, similar to the spectra sialoliths. Clinical studies showed that frequency of occurrence of urolithiasis in patients with sialic lithiasis is 43%, that significantly exceeds occurrence of sialic lithiasis in patients with urolithiasis (2%). Conducted study allows supposing that sialic lithiasis and urolithiasis are not separate diseases, but results of common complicated process of calculi formation in human organism, and must have complex treatment using medications able to prevent recurrent calculi formation in both organs. It also gives us arguments to add patients with calculous sialoadenitis to urolithiasis risk group and to provide urological assessment and prophylactic measures. According to this tactics we can also prevent sialic calculi in patients with urolithiasis.