The treat to the patient and kidney of leaving a large staghorn stone in situ in 60 cases is compared to the risk of operative removal in 125 cases. The over-all mortality rate in patients treated conservatively was 28 per cent, carcinoma developing in 4 cases and a life-threatening pyonephrosis in 16. Of patients treated by removal of the stone the mortality rate was 7.2 per cent (during 10 years of observation) and stones recurred in 21 cases. These studies refute the notion of the silent staghorn calculus and demonstrate that operative removal is safer for the patient and kidney.