Two patients presented with passage of worm-like stent fragments in the urine. The first had undergone attempted percutaneous removal of left renal calculus and ureteral stenting 4 months prior to presentation. The second had left-sided stent placement for obstructive anuria on account of bilateral renal calculi 3 months earlier. The stents had fragmented into multiple pieces over a mean indwelling time of only 3.5 months. Apart from calculus disease, both patients had documented urinary tract infection. Stent fragmentation is a relatively rare (0.3%) but major complication. However, spontaneous excretion of these fragments has not been hitherto reported. These cases of rapid stent disintegration highlight the need for closer monitoring of the indwelling stents, especially in patients with calculus disease and associated persistent infection. In such patients the stent should probably be changed within 3 months.