Urologic diseases such as urolithiasis, anomalies of the kidney and efferent urinary tracts as well as pyelonephritis and, more rarely, tumors of kidney and urinary bladder can be the cause of surgical operations during pregnancy. Inflammation is the most frequent complication starting from the urinary tract during pregnancy. Diagnosis and therapy have to take into consideration consequences arising from these examination techniques. The special problems of treatment of malign tumors of kidney and urinary bladder, and pregnancy after transplantation and ureterobowel implantation will be reported.