The course of urogenital tuberculosis is complicated by unspecific bacterial infections of the urinary tract and nephrolithiasis. Among 605 patients with bacteriological or histological verified urogenital tuberculosis, 122 patients (20%) developed unspecific bacterial urinary infection--commonly caused by E. coli, proteus and pseudomonas--and 57 patients (9.4%) showed nephrolithiasis. In 42% of the lithiasis patients an urinary tract infection simultaneously occurred. 22 calculi are analyzed by the combined crystal-optical and x-ray-diffraction method with following results: 9 X struvite/carbonate apatite, 6 X calcium phosphate, 7 X calcium oxalate. The texture of 12 calculi was investigated on thin sections by polarization microscopy and a high concentration of organic material was found in both calcium oxalate and struvite/carbonate apatite calculi.