A review of 910 cases is presented, with regard to the late consequences of pyelonephritis in pregnancy affecting both the mother and the child. Late recurrences of pyelonephritis in the mother and pyelonephritis in the child have been likewise registered. According to statistical figures, pyelonephritis in pregnancy greatly increases the hazard of calculus formation. The necessity for a long-term follow-up of mother and child after pyelonephritis in pregnancy is stressed. The significance of the measures to be taken in case of asymptomatic bacteriuria is pointed out.