An analysis was carried out of 362 infants with urinary system infections (USI) hospitalized in the years 1987-91. Using USG and X-ray examinations abnormalities were found in 90 cases (24.9%), half of which were vesicoureteral refluxes. Of interest was the correlation of USI in the infants with such things as: weight deficiency (896 cases--26.5%), diarrhoea (130 cases--35.9%), malabsorption syndrome (20 cases--5.5%). Effective treatment of USI caused simultaneously a regression of gastrointestinal sings which indicated the aetiological and pathogenetic correlation between these two facts.