Case 1: A 31-year-old woman with the chief complaint of right back pain was referred to our hospital. She was diagnosed with a right ureteral stone and it was delivered spontaneously after conservative medical therapy. The stone was found to consist of silicate by infrared spectrometry. Case 2: A 71-year-old man with the chief complaint of asymptomatic macrohematuria was referred to our hospital. No tumor was observed by cystourethroscopy, but a right ureteral stone was found by computerized tomography. Subsequently, it was delivered immediately and infrared spectrometry of the stone demonstrated silicate containing a small amount of calcium oxalate monohydrate. We analyzed and discussed 44 cases of silicate urolithiasis reported in Japan.